James Stark (https://www.flickr.com/photos/jamescstark/)
Corrado Francolini (https://www.flickr.com/photos/ohmygeekness/)
Arthur Beisang IV (https://www.flickr.com/photos/abiv/)
ilovewireframes (https://www.flickr.com/groups/ilovewireframes/)
http://blog.teamtreehouse.com/20-steps-to-better-wireframing/
http://userpathways.com/2008/06/the-what-when-and-why-of-wireframes/
https://www.smashingmagazine.com/2016/02/create-content-wireframes-for-responsive-design/