My friend Lisa sent me the link to what is I think is one of the most comprehensive vintage poster resources, Chisholm Larsson Poster Gallery. It's been around for more than 30 years in New York and features over 35,000 classic advertising posters from the 1890s up to today, including over 15,000 original movie posters. Categories like Art Nouveau, Art Deco product, liquor posters, travel, airlines, Cappiello, Cassandre, ocean liners, trains, fashion, politics ( Spanish Civil War, WW1, WW2, Propaganda and Civil Rights ), theatrical and film are all covered. The beauty is that most of their posters are cataloged and for sale on the website, go check it out. The bottom left poster shown above is actually one that Lisa owns, a French poster circa 1980's "Jean Luc Godard - Agnes B", $250—there's only one left!