We’ve recently learned about a fascinating new resource for the study of the histories of film and radio: the Media History Digital Library. This project offers high-quality reproductions of a wide range of media-related periodicals from 1904-1973, spanning from popular magazines like Photoplay to more specialized technical periodicals.
Periodicals in this collection offer a full-text search feature, additionally useful for researchers. You can read an FAQ for the project here, or take a look at their blog about items of interest from the periodicals and updates to the archive.
Anyone interested in 20th-century media history will enjoy this collection and find it an excellent resource!