The observations and notes on various documents made by Lenin during the Soviet era show his unceasing interest in the issues of Marxist theory and its development in the conditions of the beginning of socialist construction, as well as his resolute stance against any attempts to misinterpret and distort Marxism.

A brilliant example of this is the observations and notes on N.I. Bukharin's book The Economy of the Transitional Period made by Lenin in 1920, which are published in the Collection.