"Literary Source Studies" - the last work of the Corresponding Member USSR Academy of Sciences N.F. Belchikova (1890-1979). On great personal experience, the experience of outstanding literary scholars of the 20-30s and modern researchers, the author develops the theory of auxiliary disciplines of literary criticism: bibliography, archeography, textology, archival studies. Separate chapters of the book are devoted to the importance of documents of the creative process for the work of a literary critic, classification of literary sources, issues of attribution, dating, commenting.