1. 1. Schnell, H. and Bottenbruch, L. German Patent 1,229,101 (1966)
2. 2. (b) Schnell H. and Bottenbruch, L. Belgian Patent 620 620 (1960)
3. 3. (c) Schnell, H. and Bottenbruch, L. Makromol Chem. 57, 1 (1962).
4. For example, see: (a) Ivin, K. J. and Saegusa, T. (Eds.) Ring-opening Polymerization, Elsevier Applied Science, London, 1984. Vols 1-3; (b) McGrath, J. E. (Ed.) Ring-opening Polymerization: Kinetics, Mechanisms, and Synthesis, ACS, Washington, D.C., 1985. (c) Brunelle, D. J. (Ed.) Ring-opening Polymerization: Mechanisms, Catalysis, Structure, Utility, Hanser, New York, 1993. (d) Semlyen, J. A. (Ed.) Cyclic Polymers, Elsevier Applied Science, New York, 1986. (d) Schill, G. Catenanes, Rotaxanes, and Knots, Academic Press, New York, 1971.
5. Rossa, L. and Vögtle, F. Top. Curr. Chem.
113, 1 (1983).