Guidelines on the Common Features of Mobile Phone Interfaces
http://www.serco.com/Images/Mobile_phone_guidelines_final-1_tcm3-21169.pdf

Stockbridge, Lucy and Azia Mughal
Serco
2007

Abstract:

An ever increasing range of mobile phones are appearing on the market, each with their own features, designs and interfaces. Our extensive experience of working with a wide range of phones suggests that, despite their many differences, there are some user interface requirements common to all mobile phones. These requirements are presented as guidelines below.