1. Staverman, A. J. andF. Schwarzl, in: Die Physik der Hochpolymeren. Edited by H. A. Stuart (Berlin 1956) Vol. IV, pp 63–69; pp 86–88; pp 25–28; p 88.
2. Markovitz, H., J. Appl. Phys.34, 21–25 (1963).
3. Ferry, J. D., Viscoelastic Properties of Polymers (New York 1961) pp. 118–122.
4. Brinkman, H. C., Internal Communication No. 55/22 (1955).
5. Elder, A. S., Trans. Soc. of Rheology9, 187–212 (1965).