Brian McNair's An Introduction to Political Communication
The chapter on political advertising is of most relevance to our research on election posters.
McNair, Brian, 1999. An Introduction to Political Communication, Second Edition. Routledge. ISBN 0-415-19921-2.This book is an undergraduate textbook, but it does provide some useful pointers to previous research on political advertising in the United States and Britain. I must find, for example, Kaid et al., ads., New Perspectives in Political Advertising (1986). McNair also points out that it is relatively rare for advertisements to articulate policies, and (quoting Diamond and Bates' The Spot) that the first phase of a US advertising campaign is to establish the basic identity of a candidate.

