1. R. Heygate How to build valuable customer relationships 2001
2. http://www.crm-forum.com/library/sophron/sophron-022/brandframe.html
3. P. Stevens J. Hegarty 1999
4. http://www.crm-forum.com/library/sophron/sophron-002/brandframe.html
5. Banner blindness: web searchers often miss obvious links;Benway;Internetworking,1998