1. United States Department of Commerce, National Bureau of Standards, Washington, D.C. 20234, U.S.A.
2. Pressure Chemical Co., 3419–25 Swallman Street, Pittsburgh, U.S.A.
3. Toyo Soda Manufacturing Co., Ltd., Toso Building, 1–7–7 Akasaka, Minato-ku, Tokyo 107, Japan.
4. The Fractionation of High-Polymeric Substances.
5. ‘Techniques of Polymer Characterisation’ ed. 1959, Ch. 2, London: Butterworth.