5.1 Internet Sources.
- https://www.hbr.com
- https://www.palgrave-journals.com
- https://www.positioneringsgroep.org
- https://faculty-gsb.stanford.edu/aaker/
- https://www.marketingpower.com
- https://www.prophet.com
- https://www.eurib.org
- https://new.zanthus.com
- https://www.cat.com
- https://brand.cat.com (secured web site)
- https://www.interbrand.com/en/best-global-brands/previous-years/best-global-brands-2007.aspx
- https://cgi.money.cnn.com/tools/fortune/custom_ranking_2008.jsp
- https://en.wikipedia.org
- https://www.flickr.com/photos/mleak/sets/72157601527097498/ Cover photo Emily Berezin, May 15th 2008.