The papers consist primarily of the Kosatkin-Rostovskiĭ's memoirs. His manuscript memoirs (150 p.) discuss his life up to 1906. Her typescript memoirs (440 p.) discuss her childhood, career as an actress in St. Petersburg, 1917-1918 in Petrograd, and the emigration in France. Also included are his diary for June-July 1940; a few letters written to him; clippings of his newspaper articles (many signed with the pseudonym "Antar"); and a book with his poetry and with essays dedicated to him; "Krestnym putem k voskresenii︠u︡" (Paris, 1948).

Collection includes 19 manuscript notebooks of poetry and prose; 42 titled articles in typescript form on religious, political, literary and autobiographical topics; several published collections of her poetry; and a folder of original drawings. Also included are three biographical articles by K. Mochulśkiĭ, M. Vishni︠a︡k and her mother Sofii︠a︡ Borisovna Pilenko, as well as her own childhood and that of her mother and grandmother during the era of Alexander I, Nicholas I, and Alexander II.