Chess problems of the 19th century
The history of the chess problem in the 19th century, country by country.
E. I. Umnov
Modern chess problem
The basic concepts, principles of construction and features of different chess problem genres.
The Chess Problem of the 20th Century. 1901–1944
The development of the chess problem from 1901 to 1944: new schools, ideas and technique.
Ways of chess creativity
E. Umnov on chess history, the development of studies and problems, and endgame theory.