Kuromiya, op. cit., pp. 304–305.

Progres, op. cit., p. 26.

Progres, op. cit., p. 31.

R. W. Davies. The Industrialisation of Soviet Russia I: The Socialist Offensive; The Collectivisation of Soviet Agriculture, 1929–1930 (Cambridge, Massachusetts: Harvard University Press, 1980), pp. 4–5.