
Konstantin Somov, Portrait of Mikhail Kuzmin, 1909. Water-colours, gouache and whiting on paper pasted on cardboard. The Tretyakov Gallery

Konstantin Somov, Portrait of Alexander Blok, 1907. Lead pencil, crayons and gouache on paper. The Tretyakov Gallery

Boris Kustodiev, Portrait of Georgi Vereisky, 1917. Lead pencil and sanguine on paper. The Russian Museum
Source: Russian Portrait of the late 19th-early 20th centuries, I. Pruzhan, V. Kniazeva, Izobrazitelnoye Iskusstvo Publishers, Moscow, 1980