1. Leibniz , On the Elements of Natural Science, Loemker ed., vol. i, sect. 32, pp. 426–447, especially p. 439.
2. Gilson E. , Commentaire, pp. 181–182, 187, 195, 222, 223.
3. Dijksterhuis E. J. , ‘La Methode et les Essais de Descartes’, in Descartes et le Cartesianisme Hollandai, 1950, by various writers, pp. 21–44
4. Milhaud G. , Descartes Savant, 1921, Ch. 5, especially pp. 108–117