A number of French online electronic libraries exist where you can find texts that are unavailable on the shelves of the library. Here are a few. Some of them are available via Databases A-Z.
Cambridge Companions Online offer many titles of relevance to French literary studies (and only a selection is offered here). Not only are there companions to particular authors such as Baudelaire, Flaubert, Zola but also on more general topics such as the French novel, French culture or medieval French literature. There are quite a few studies devoted to French writers working in related fields such as education (Piaget), religious philosophy (Malebranche). There are also a large number of studies on broader themes such as science fiction, postmodernism, modernism, children's literature, the literature of World War II, gay and lesbian literature, the African novel, crime fiction which will have much material relevant to French literary studies.