"International Posters: A Collector's Primer" by Jim Lapides

When the predominantly American market for vintage posters emerged in the late 1970s, attention focused on French Art Nouveau and Art Deco artists like Toulouse-Lautrec, Alphonse Mucha, and A.M. Cassandre.  As the poster market has matured and spread globally, however, interest has broadened to include styles and subjects from nearly every era and country... The market has also strengthened for many category niches such as travel, sports, and war posters, which continue to yield auction records despite the recession.