1. Root:shoot ratio as a balance between nitrogen productivity and photosynthesis;Ågren;Plant, Cell and Environment,1987
2. The formation and nitrogen-fixing ability of Alnus glutinosa under field conditions;Akkermans,1975
3. Alden, T. (1971) Influence of CO2, moisture and nutrients on the formation of lammas growth and prolepsis in seedlings of Pinus sylvestris L. Studia Forestalia Suecica93, 21
4. Allen, L.M., Beladi, S.E. and Shinn, J.H. (1985) Modelling the feasibility of free-air carbon dioxide releases for vegetation response research. 17th Conference on Agriculture and Forest Meteorology and 7th Conference on Biometeorology and Aerobiology, Scottsdale, Arizona. A&F 9.4, pp.161–164. American Meteorological Society, Boston
5. Possible effect of changes in atmospheric composition and acid rain on tree growth;Arovaara;Communicationes Instituti Forestalis Fennicae,1984