Lev Nikolaevich Tolstoĭ. Materialy i biografii s 1870 po 1881 god /
Academy of Sciences of the Union of Soviet Socialist Republics (Moscow). - A.M. Gorʹky Institute of World Literature.
Gusev, N. N.(Nikolaĭ Nikolaevich),1882-1967.
Shifman, A. I.
Moskva,
1963.