1. Buchdahl, Gerd, (1969) Metaphysics and the Philosophy of Science, Basil Blackwell, Oxford
2. Hume, David (2000) A Treatise of Human Nature, Oxford University Press, Oxford
3. Hume, David (1825) History of England, in eight volumes, T. and J. Allman, London
4. Jammer, Max (1957) Concepts of Force, Dover Publications