1. Sernander, R., Geol För. Stockh. Förh., 31, 423–448 (1909).
2. Aaby, B., and Tauber, H., Boreas, 4, 1–17 (1974).
3. Damon, P. E., Long, A., and Wallik, E. J., Proc. int. Dating Conf., New Zealand, A28–A43 (1973).
4. Aaby, B., Geol. Surv. Den. Yb. 1974, 91–104 (1975).
5. Clymo, R. S., J. Ecol., 53, 747–758 (1965).