N.S. Kartashov's contribution to the branch science methodology: conception of comparative librarianship

The article exposes N.S. Kartashov's contribution to the branch science methodology in the following directions: working out the conception of comparative librarianship, defining its essence, tasks, object, subject, principles; proving the specificity of comparative librarianship method, substantiating its postulates, means of realization; introducing precise research practices of using the comparative librarianship method.