1. V. Shlapentokh, Soviet Intellectuals and Political Power: The Post-Stalin Era (Princeton, 1990) p. 239.
2. Bertram Wolfe, The Bridge and the Abyss: The Troubled Friendship of Maxim Gorky and V.I. Lenin (London, 1967) p. 157.
3. Neil Harding, Lenin’s Political Thought 2 vols (London, 1977; 1981)
4. Robert Service, Lenin: A Political Life 3 vols (London, 1985; 1991; 1994)
5. James D. White, Karl Marx and the Intellectual Origins of Dialectical Materialism in Russia (Basingstoke, 1996)