1. Ahti, T., Hämet-Ahti, L., Jalas, J.: Vegetation zones and their sections in northwestern Europe. Ann. Bot. Fennici 5, 169–211 (1968)
2. Alm, B., Enemar, A., Myhrberg, H., Svensson, S.: The density of birds in two study areas of the alpine region in southern Lapland in 1964. Acta Univ. Lundensis II, 4, 1–14 (1965)
3. Alm, B., Myhrberg, H.E., Nyholm, E., Carlsson, U.T., Svensson, S.: Structure and dynamics of a bird community on alpine tundra in Swedish Lapland over a nine year period. Redogörelse för LUVRE-symposiet, Stensoffa, 10. 3. 1973. Mimeogr., 7 pp. (1973)
4. Alm, B., Myhrberg, H.E., Nyholm, E., Svensson, S.: Densities of birds in alpine heaths. Vår Fågelvärld 25, 193–200 (1966)
5. Anon: Recommendations for an international standard for a mapping method in bird census work. Bull. Ecol. Res. Comm. (Lund) 9, 49–52 (1970)