Prolific and enthusiastic commentator, historian and bibliographer of Russian classical literature. Compiled a Biographical Dictionary of Russian Writers, 6 vols, 1886-1904. Wrote monographs on many 19th century writers.
Prepared the first full edition of the works of Belinskii in 13 vols. Editor of the literary section of the Brockhaus and Efron Encyclopaedia. Founder and first chairman of the Rossiiskaia Knizhnaia Palata (Russian Chamber of Books), 1917.