1. N. K. Adam, Physics and Chemistry of Surfaces (Oxford, 1930).
2. R. Chambers, The Physical Structure of Protoplasm in General Cytology, edited by E. V. Cowdry (Chicago, 1924).
3. J. Gray, Textbook of Experimental Cytology (Cambridge, 1931).
4. W. D. Harkins, Surface Energy and Surface Tension in Colloid Chemistry, edited by J. Alexander, Vol. I (New York, 1926).
5. L. V. Heilbrunn, The Colloid Chemistry of Protoplasm (Berlin, 1928).