Credit

Animals

123RF
A1 Free Sound Effects
Alamy Images
Ardea
Art Life Images
AudioJungle
AudioSparx
BigStockPhoto.com
Blue Yonder
Brand X Pictures
Can Stock Photo
Comstock
Corbis
Creatas
Digital Stock
Digital Visions
Dreamstime
Dwight Kuhn
Florida Keys National Marine Sanctuary
Footage Search
fotolia
Freesound
Getty Images, Inc.
Hollow Haven Farm
Image Source/elektraVision
image100
iStockphoto
James P. Rowan Photography
Jim Kennedy
Jon Hughes
Karon Dubke
Marine Themes Pty. Ltd.
Minden Pictures
Nature Picture Library
Newscom
Newspix
Patrick Coin
Peter Arnold, Inc.
Photo Researchers, Inc.
PhotoAlto
Photodisc
Photolibrary
Photos.com
Photoshot Holdings Limited (Bruce Coleman)
productiontrax
Rose Gums Wilderness Retreat
SeaPics
ShutterPoint
Shutterstock
Simply the Best Sounds
Sounddogs
Sound-effect.com
soundsnap
Thought Equity Motion
Visuals Unlimited
Wild Wind Images

Animales

A highly qualified team of experts in the Spanish language translated the Animals articles into Spanish for Animales. Trusted Translations, an authority in Spanish translation services, has worked extensively to find the best in Spanish-language translators. The Animales translations were triple-verified: first by a translator, then an editor, and then finally, after audio-recording, the audio was reviewed for pronunciation and quality. All articles were translated contextually. This is important because, for example, in Spanish, animal terms can vary depending on the animal’s gender and age, whereas in English, the same term is used. All of the audio in Animales was recorded by professional voice over artists who are native Spanish speakers.

Science

Dreamstime
iStockphoto
Karon Dubke
NASA
Pond5
Science Source/Sheila Terry
Shutterstock

Biographies

5min Media
A’Lelia Bundles
ABC 36, WTVQ-DT LLC
Affordable Housing Centers of America
Alamy Images
Alexander Graham Bell National Institute
Amon Carter Museum
AP Images
Art by American Women, The Louise and Alan Sellars Collection
Art Museum of Missoula
Art on 5th
Art Resource
Atchison County Historical Society
AudioSparx
Beinecke Library
Bob Annesley
Boston University
Bridgeman Art Library
Brown Brothers USA
Bucklaw
Carlyle Urello
Carolina Holdings
Cesar E. Chavez Foundation
Clara Barton National Historic Site, National Park Service
Clymer Museum
Cold Water Media
Colonial National Historic Park, National Park Service
Connecticut Historical Society
Corbis
Courtesy of W.L. Pate, President of Babe Didrikson Zaharias Foundation
Critical Past LLC
Dan Roberts Enterprises
daredevildeanbodom
David Jensen
David Williams, Union One
Dreamstime
Dwight D. Eisenhower Library
Edison National Historic Site, National Park Service
Ellen Ochoa
Ellen Ochoa Middle School
Filson Club Historical Society
Florida State Archives
Franklin D. Roosevelt Library
Franklin Institute
Frederick Remington Art Museum
Frederick Douglass National Historic Site
Friends Historical Library, Swarthmore College
Gary R. Lucy Gallery, Inc.
George Washington Carver National Monument
Georgia Public Broadcasting
GeorgiaInfo
Getty Images, Inc.
Gettysburg National Military Park, National Park Service
Globe Photo
Google Video
Granger Collection
Haynes & Haynes, Inc. / Michael Haynes
Helen Keller Foundation
Henry Ford Museum
Howard University Archives / Moorland Spingarn Research Center
Image Works
Independence National Historical Park
Ingalls Homestead
Institut Pasteur
Invisible Cities Press
Iowa State University
iStockphoto
James Hilgendorf
Jane Goodall Institute
John F. Kennedy Presidential Library and Museum
John Ryan
Joroarkenglish
julyladyproductions
KEDT-TV
KimObrist
Lakewood Public Library
Landov LLC
Laura Ingalls Wilder Home & Museum
Library of Congress
LilliMar Pictures
Lincoln University
Line of Battle Naval Heritage Museum
Louis Armstrong House & Archives, Queens College
Magnum Photos
Margy Miles
Mary Evans Picture Library
Matt Katz
McGill University
Meriwether Productions
Miles Christian Daniels
Minnesota Historical Society
Missionaries of Charity
mjlauria
Montana Historical Society
Monticello / Thomas Jefferson Foundation
mrmigente
Museum of Springfield History
Museum of the Alphabet, JAARS, Inc.
NASA
National Baseball Hall of Fame
National Portrait Gallery, London
National Space Society
Nevada Culture
Nevada Historical Society
Nevada State Library and Archives
New Georgia Encyclopedia
New York Public Library
Newscom
Nickolas Muray Photo Archives
North Wind Picture Archives
Oklahoma Arts Counsel
PappyStu
Patrick D. Dentinger
Permission of Honeywell
Phoenix Film and Video
Photograph courtesy of Mo Willems. Reprinted by permission of Wernick & Pratt Agency LLC. All rights reserved.
Pratt Institute
Protocol Entertainment Inc.
Public.Resource.org
Reading Rockets
Redwood Audiobooks
Rieder Photography
Rosenbach Museum & Library
Sam Houston Memorial Museum
San Jacinto Museum of History
Savannahvisit.com/SavannahEst1733
Schomburg Center for Research in Black Culture, New York Public Library
Shepherd Entertainment, Inc.
Shutterstock
Smithsonian Institution, National Portrait Gallery
Smithsonian Institution, National Museum of American History
Smithsonian Institution, National Air and Space Museum
Sophia Smith Collection, Smith College
streettalkin.com
Suki Coughlan
Superstock
Supreme Court of the United States
Swarthmore College Peace Collection
Take Stock Photos
Talmadge Davis
Teachers’ Domain
Texas A&M University, Corpus Christi
Texas State Library and Archives Commission
The Brothers Einstein
The Founding Mothers
TheCitizenTAG
theinstructorchrisS
Theodore Roosevelt Collection, Harvard College Library
Thought Equity Motion
Throckmorton Fine Art, Inc.
TMW Media Group, Visionquest
Tongel Art Studio
transformingArt
University of Michigan
University of North Carolina at Chapel Hill
University of Pennsylvania, Annenberg Library
University of Rochester
University of the Pacific Library, Holt-Atherton Special Collection
University of Washington Libraries
Voices of America
watchmojo.com
Wayne State University, Walter P. Reuther Library
White House Historical Association
wikipedia
Woolaroc Museum
World Wide Entertainment Production & Sales Ltd.
Worldwide Media Organization
Wright State University
Zuma Press

Social Studies

A. T. Willett
Mary Evans Picture Library
Moodboard
Photoshot Holdings Ltd.
Stan Tess
wavebreakmediamicro
Air Force Space Command
Airphoto: Jim Wark
Alamy: Accent Alaska
Adam Eastland
Adriadne Van Zandbergen
Art Directors & TRIP
Bill Bachman
Bob Daemmrich
Bridgette Sullivan/Outer Focus Photos
David White
David Young-Wolff/PhotoEdit
dbimages
DC Premiumstock
Dinodia Photos
Everett Collection
Foto 28
Francis Roberts
Hemis
Ilene Perlman
Images & Stories
Jean Schweitzer
Jeff Smith
Jim West
Keith Morris
Kim Karpeles
Lou-Foto
Louise Batalla Duran
Luc Novovitch
MARKA
Marmaduke St. John
Michael Matthews – Police Images
Michael Ventura
Mikael Karisson
Myrleen Pearson
NetPhotos
Peter Horree
Peter Titmuss
Photo Japan
Photo Network
Rob Crandall
Rob Kavanagh
Simon Reddy
Terese Kreuzer
Tom Carter
TongRo Images
White House Photo
Witold Skrypczak
Yadid Levy
ZUMA Press
ZUMA Wire Service
Alaska Stock Images
AP Images: Bettmann/Corbis
Pablo Martinez Monsivals
Architect of the Capitol
Art Resources
N.Y.: bpk
Berlin
NGS Images Collection
AT&T Archives and History Center
Austin Public Library
Austin History Center
PICA 05476
BigStockPhoto: Cacci
Bridgeman Art Library: Corcoran Gallery of Art
Washington DC
Hall of Representatives
Washington D.C.
USA
Luca Tettoni
Peter Newark American Pictures
Stapleton Collection
Capstone Studio: GEM Group
Karon Dubke
Ludmila Serikova
Centers for Disease Control and Prevention
Corbis: Bettmann
Charles & Josette Lenars
Erich Schlegel
fb.anggoro
Galen Rowell
Harry Choi/TongRo Images
Jack Fletcher/National Geographic Society
R. Krubner/ClassicStock
Tim Pannell
Tom Koene/Visuals Unlimited
Courtesy of Army Art Collection
U.S. Army Center of Military History
Creatas
David S. Eves
Department of Rare Books and Special Collections
University of Rochester Libraries
DoD photo by Don Lindsey
U.S. Air Force
Dreamstime: Elena Elisseeva
Eric Broder Van Dyke
Glen Jones
Iofoto
Joshua Haviv
Walter Arce
Fotolia
Franklin D. Roosevelt Library
GeoBeats
Getty Images: AFP
Alex Wong
Andrew Harrer/Bloomberg
Archive Films
Erik S. Lesser
FPG
Grey Villet/Time Life Pictures
Grooters Productions
H. Armstrong Robers/Retrofile
Halcyon Days
Hulton Archive
Image Bank Film
Image Film Bank
iStockfootage
Lewis W. Hine/Buyenlarge
MacNeil/Lehrer
Malcolm Ali/WireImage
Michael Ochs Archives
Ralph Crane/Time & Life Pictures
Robert W. Kelley/Time Life Pictures
Saul Loeb/AFP
Seelig/NY Daily News Archive
The Washington Post
Stan Wayman/Time Life Pictures
Steffan Hill
Stock Connection Blue
Three Lions
Topical Press Agency
Underwood Archives
Vintage Images
William Thomas Cain
Independence National Historical Park
iStockphoto: Alija
Alina555
ansolovei
AvailableLight
BanksPhotos
benjikat
benlynn
BrentYoung
clearandtransparent
colematt
ConstanceMcGuire
DarrenMower
Dean Mitchell
EVAfotografie
Frank Leung
Grafissimo
GreenPimp
ilbusca
inhauscreative
IsaacKoval
iShootPhotos
jabejon
JamesBrey
JaniceRichard
Jason Field
JBryson
Jixxer
jsmith
juanmonimo
kali9
katalinamas
kozmoat98
ktaylorg
LeggNet
lostinbids
lucop
Maica
morganl
mujdatuzel
multifocus
neilmercer
nicolesy
nkbimages
NNehring
nycshooter
OneStoneMedia
P Wei
PurpleVideos
RGtimeline
RiverNorthPhotography
simonkr
sjlocke
Studio1One
thomasd007
tillsunburg
tirc83
Todd Keith
tovfla
uberstock
vgajic
VikramRaghuvanshi
webphotographer
Willowpix
YinYang
Kids.gov
Library of Congress
Lori Bye
Macomb County Bar Foundation and Sterling Heights Television
NASA: GRIN
Ken Glover
National Archives & Records Administration
National Park Service: Abbie Rowe
Courtesy of Harry S. Truman Library
Newscom: Bradley Lail – USAF via CNP
CMSP Education
Icon SMI 007/Chris Williams
Kimberly White/Reuters
Michael Dalder
Owen
Picture History
Reuters
ZUMA Press
NOAA
North Wind Picture Archives
PhotoEdit: James Shaffer
Michael Newman
Tom Carter
Pond5: AchimHB
beeto
bscott87
Burlingham
chris wsw
egleye
emmanualc
holtocw
ImageSource
jasonprisk
joelpackman
KingWu
kk5hy
raywoo
rus009
sheyno
Starbirdprod
TheEngineer
u6547066
victorchb
WorldViewImages
yatmaca
youseehim
Shaun Errichiello
Shutterstock: 3 song photography
A Cotton Photo
A.R. airphoto.gr
AISPIX by Image Source
Alena Ozerova
Aletia
Alex Garaev
Alexey Kamenskiy
Alinute Silzeviciute
Alsu
amahuron
Anastasios71
Andi Berger
Andrew F. Kazmierski
Anne Kitzman
Annemarie van Oudenaren
Anthony Correia
Antonio Abrignari
antos777
Apollofoto
AridOcean
ArnaudS2
ArTono
Arvind Balaraman
ARZTSUMUI
Asianet-Pakistan
auremar
AVAVA
ayosphoto
Belinda Pretorius
benta stewart
BigfootHD
bikeriderlondon
Blend Images
BMCL
Bobby Deal/RealDealPhoto
Bochkarev Photography
bonchan
Brandon Seidel
branislavpudar
Brocreative
C.
CandyBox Images
Carlos Neto
Carly Rose Hennigan
Catalin Petolea
ChameleonsEye
Charlie Edward
Chris Howey
Christa DeRidder
Christian de Araujo
Christophe Testi
Christopher Halloran
chromadreamcoat
Chuck Aghoian
ckciu
Cora Reed
corepics
cozyta
cynoclub
Cynthia Farmer
Dave Newman
David Aleksandrowicz
David Lobos
Dawn Shearer-Simonette
Denis Kuvaev
Denis Saraginovski
Diego Cervo
dinadesign
Distinctive Images
Dmitriy Shironosov
Dmitry Kalinovsky
DonaldBowers
dream one
dualstock
Dubova
Elena Elisseeva
Elizabeth C. Doerner
Eugene
Berman
Faraways
Felix Mizioznikov
Feoktisoff
Fffooter
Florinikus
Fotokostic
Fotonium
Francesco Dazzi
Franck Boston
Frontpage
fstockfoto
Gary Blakeley
Gary Whitton
fary718
Gemenacom
George P. Choma
Glenda M. Powers
gnomeandi
Gorilla
gosphotodesign
Greg Kushmerek
GSPhotography
guentermanaus
guynamedjames
Hasan Shaheed
Holger W.
imageegami
imagesolutions
Ingvar Bjork
Jaimie Duplass
James K Troxell
James Steidl
James Steig
jamesdeanny
Jane September
Jaren Jai Wicklund
Jason Stitt
Jeanne Hatch
JHDT Stock Images LLC
jiawangkun
Jim Barber
Jim Vallee
John Kasawa
John Roman Images
JohnKwan
Jose Gil
Josemaria Toscano
Joseph Becker
Juriah Mosin
JustASC
Kamira
karamysh
Keith McIntyre
Kenneth Sponsier
kolo5
Konstatntin L
Konstantin Sutyagin
Kushal Bose
Lane V. Erickson
lenetstan
Lisa
F. Young
Lisa S.
Lisette van der Hoorn
Lissandra
Lori Sparkia
Losevsky Photo and Video
Lucian Coman
Luis Santos
Luis Stortini Sabor aka CVADRAT
Lukasz Kurbiel
M Reel
majeczka
mangostock
Marcel Clemens
Margo Harrison
Maridav
Marilyn Volan
Mark R
Markus Gebauer
mart
Matej Hudovernik
matka Wariatka
Max Tipchii
MaxyM
MCarter
Melanie DeFazio
Mi.Ti.
michaeljung
Mike Neale
Mikhail Levit
MJTH
MO:SES
Monkey Business Images
Morgan Lane Photography
Mr Doomits
Muriel Lasure
My Good Images
My Portfolio
Naiyyer
Nancy Gill
nbiebach
Nigel Paul Monckton
nikkytok
Nikolpetr
Noam Armonn
Noel Powell
Schaumburg
Ochkin Alexey
OLJ Studio
Orhan Cam
Orietaly
OtnaYdur
Pablo77
Patryk Kosmider
Paul Banton
Paul Frederick
Paula Cobleigh
PavelSvoboda
Peeradach Rattanakoses
Perry Correll
Pete Niesen
Peter Bernik
Peter Kim
Petunyia
Phaitoon Sutunyawatchai
Pierre Yu
pinggr
PiyachatS
prochasson Frederic
r0ma4
Racheal Grazias
ringizzz
Raywoo
Rekindle Photo and Video
Remco Ahne
Richard Kelly
Richard Upshur
Rigucci
Rob Hainer
Rob Marmion
Robert Kneschke
Robert Kylio
Ronald Caswell
rsooll
Rudy Balasko
runzelkorn
Ryan E. Walters
S.Borisov
salajean
Samson Yury
sauletas
SeanPavonePhoto
Simon Krzic
skphotography
Smailhodzic
Smileus
Solaria
sonya etchison
sowar online
spirit of America
spotmatik
Star Painter Productions
Starbird Productions
Stefan Ataman
Steffen Foerster Photography
Stephane Bidouze
Stephen Bures
Steshkin Yevgeniy
Steve Byland
Steve Collender
Steve Cukrov
steve estvanik
Steve Heap StockThings
Straigth 8 Photography
Stuart Monk
Supri Suharjoto
Suzanne Tucker
SVLuma
swissmaky
Szasz-Fabian Ika Erika
Szczups
Tatiana Belova
Tereshchenko Dmitry
Terrie L. Zeller
Thomas M Perkins
Tim Roberts Photography
Timothy R. Nichols
tipograffias
Tom Cummins
Tom Gowanlock
tomas del amo
Tomas Skopal
Thomas Urbelionis Photo
Tony Magdaraog
TonyV3112
Transcendental Media
trekandshoot
trubach
TTphoto
Tupungato
twistah
Tyler Olson
Vacclav
vadim kozlovsky
ValeStock
Varina and Jay Patel
Vasily Kovalev
Vepar5
Victorian Traditions
Vitalinka
Vladimir Wrangel
Vsevolod33
Wallenrock
wandee007
wavebreakmedia ltd
Waxen
Weldon Schloneger
Wessel du Plooy
wong yu liang
xbrchx
YanLev
Yarek Gora
Yuri Arcurs
Yuriy Kulyk
zirconicusso
ZouZou
Zurijeta
Sprout
Stockbyte
Svetlan Zhurkin
The White House: Chuck Kennedy
U.S. Army photo by Staff Sgt. Felix R. Fimbres
U.S. Geological Survey
United States Department of Agriculture
Wikimedia
Wikipedia: Daderot
YouTube: CityofEvansvilleIL
Coventry University
Learn Media of America
MNStateLegislature
TeacherTube
The White House
US Courts
US National Archives
videosporalex

Health

Amber Chandler - National Board Certified Early Adolescent English teacher, Curriculum and SEL Consultant to Thomas B. Fordham Institute, 3-time awardee of the NoVo Foundation SEL in Action Grant and recipient of Teaching Tolerance Classroom grant, Author of The Flexible Social Emotional Classroom and The Flexible ELA Classroom
Dr. Jennifer Johnson - Instructor, Mayo Clinic College of Medicine, Department of Family Medicine
Dr. Matt Avey - Curriculum & Instruction- Lincoln Public Schools, Curriculum Specialist K-12 Health & Physical Education

Open Source Library

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provide with the distribution.
Neither the name of Neuman Vong nor the names of other contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.