1. Aario, L., 1940. Waldgrenzen und subrezenten Pollenspektren in Petsamo Lappland. Annales Academiae Scientarum Fennicae A 54(8), 120 pp.
2. Allen, T. F. H., R. V. O’Neill, and T. W. Hoekstra, 1984. Interlevel relations in ecological research and management: some working principles from hierarchy theory. USDA Forest Service, General Technical Report RM-110, 11 pp.
3. Andersen, S. T., 1967. Tree-pollen rain in a mixed deciduous forest in south Jutland (Denmark). Review of Palaeobotany and Palynology 3: 267–275.
4. Andersen, S. T., 1970. The relative pollen productivity and pollen representation of north European trees, and correction factors for tree pollen spectra. Danmarks Geologiske Undersogelse II 96, 99 pp.
5. Andersen, S. T., 1973. The differential pollen productivity of trees and its significance for the interpretation of a pollen diagram from a forested region. In: H. J. B. Birks and R. G. West (eds.) Quaternary Plant Ecology, pp. 109–115, Blackwell, Oxford.