1. Hooke R (1672) On holes (black film) in soap bubbles. Commun R Soc Mar 28.
2. Newton SI (1730) Opticks or, A Treatise of the Reflections, Refractions, Inflections, and Colours of Light (R Soc, London).
3. Plateau J (1873) Statique Expérimentale Et Théorique Des Liquides Soumis Aux Seules Forces Moléculaires (Gauthier-Villars, Paris).
4. Courant R Robbins H (1941) What Is Mathematics? (Oxford Univ Press, London).
5. II. Experimental researches in electricity. ─twenty-fifth series