1. Sussman, A. H. Halvorson, Spores, Their Dormancy and Germination pp. 40–51, Harper & Row (1966).
2. Ibid. pp. 40-41
3. Rogers, H. J., H. R. Perkins, Cell Walls and Membranes, p. 372, E. & F.N. Spon Ltd. (1968).
4. Bungenburg de Jong, H. G., Proc., Acad. Sci. Amsterdam 41, p. 646, (1938).
5. Bungenburg de Jong, H. G., Kass, Biochem. Zeit., 232, p. 338, (1931).