1. Long-term ecological research;Callahan;Bioscience,1984
2. Strayer, D. et al. (1986) Long-Term Ecological Studies: An Illustrated Account of Their Design, Operation, and Importance to Ecology, Occasional Publication of the Institute of Ecosystem Studies (no. 2), Institute of Ecosystem Studies
3. Likens, G.E., ed. (1989) Long-Term Studies in Ecology: Approaches and Alternatives, Springer-Verlag
4. The Ecosystem Approach: Its Use and Abuse;Likens,1992
5. Monitoring for Conservation and Ecology;Goldsmith,1991