1. Aristotle: 1996, Physics. Trans. Waterfield, R. Oxford University Press, Oxford.
2. Bachelard, G.: 1934, The New Scientific Spirit. Trans. Arthur Goldhammer, Beacon Press, Boston.
3. Bachelard, G.: 1940, The Philosophy of No. Trans. G.P. Waterston, Grossman Publishers, New York.
4. Constructivism: A theory of knowledge