Licence Stock Photos
attribution or back link needed
http://allthefreestock.com/
https://www.bigstockphoto.com/...
http://www.canstockphoto.com/
http://www.clipart.com/en/
https://commons.wikimedia.org/...
http://compfight.com/ associated with Flickr
http://www.deviantart.com/
https://www.dreamstime.com/ You can advertise Dreamstime and earn here
http://www.everystockphoto.com...
https://www.flickr.com/creativ...
https://www.flickr.com/photos/...
https://nl.fotolia.com/
http://www.freedigitalphotos.n...
http://www.freefoto.com/index....
http://nl.freeimages.com/
http://www.freeimages.co.uk
http://www.freepik.com/
http://freestock.ca/
http://www.freestockphotos.biz...
http://www.gettyimages.co.nz/c...
http://gratisography.com/
https://www.iconfinder.com/
http://www.iconspedia.com/
http://www.lifeofpix.com
http://nl.freepik.com/
https://www.nps.gov/features/y...
http://photopin.com/ associated with Flickr
https://www.shutterstock.com
http://thestocks.im/
https://us.fotolia.com/
Sincerely, Dr. Marilyn M. Carr