Litmus

http://www.litmusbranding.com/

Hidden

15 Famous
http://www.lifebuzz.com/logos/
19 Sports
http://ftw.usatoday.com/2014/10/sports-logos-hidden-messages-images-fedex-montreal-canadiens 
20 Clever
http://twistedsifter.com/2011/08/20-clever-logos-with-hidden-symbolism/ 
25 Famous
http://list25.com/25-famous-logos-with-hidden-images/ 
40 Brands Logos
http://www.creativebloq.com/infographic/40-brand-logos-hidden-messages-101413222 
50 Clever
http://digitalsynopsis.com/design/50-clever-hidden-meaning-logo-designs/
55 Creative Logo Designs
http://webneel.com/webneel/blog/55-creative-logo-designs-hidden-messages-find-it-now

100
http://100picsquizanswers.com/
http://www.100pics-answers.org/
http://100-pics.org/

Tube
https://www.youtube.com/results?search_query=Hidden+Images+in+Brand+Logos 

inter

http://www.interbrand.com/en

http://www.interbrandhealth.com/ 

National Branding / PPT / Corporate

http://en.wikipedia.org/wiki/Nation_branding
http://nation-branding.info/
www.infobalt.lt/docs/MortenScholer.ppt

Magic

http://brand-magic.co.uk/case-studies/
http://www.brandmagic.tv/ 
http://www.brandmagic.se/
http://www.brandmagic.ie/index.php/casestudies/ 

Stray dog

http://straydogbranding.com/

Glossary

http://testmonki.com/brand-glossary.html

Links
http://www.stealingshare.com/brand_resources/glossary/