Bion, W.R.
(1978) in F.B. (ed.) Four Discussions with W.R. Bion, p. 16. Strath Tay: Clunie Press.
2.
Laing, R.D.
(1967) in The Politics of Experience, p. 45. Harmondsworth: Penguin.
3.
Marx, K.
(1845) `Theses on Feuerbach', in S. Ryazaskya (ed.) The German Ideology by Karl Marx and Friedrich Engels, p. 645. London: Lawrence and Wishart, 1965.
