Postal stationery has a rich tradition of philatelic literature. Specialized journals specializing in postal stationery have been around since the late 1800s. Today they can be found in various languages. A list of journals and contact information can be found here. General books and catalogs can be found here. Books devoted to one country or area can be found here. As part of the electronic age CDROMs are starting to appear. Reviews also can be found.
The list is by no means exhaustive. Please send additional listings and reviews to Ross Towle for inclusion..
I would like to thank André Hurtré for graciously allowing me to us his Essai de Bibliographie des Entiers Postaux du Monde as the source for many of the entries.