1. Bader, C. (1975) Ergebn. wiss. Unters. Schweiz. Natn Parks, 14, 1–270.
2. Berthon, J.L. (1980) C.R. Acad. Hebd. Séanc. Sci. Paris, 286, 899–900.
3. Braumann, T. and Grimme, L.H. (1981) Biochim. Biophys. Acta, 637, 8–17.
4. Chapman, D.J. and Haxo, F.T.V. (1963) Plant Cell Physiol., 4, 57–63.
5. Cheesman, D.F., Lee, W.L. and Zagalsky, P.F. (1967) Biol. Rev., 42, 132–160.