Anaerobic digestion 1981: D. E. Hughes, D. A. Stafford, B. I. Wheatley, W. Baader, G. Lettinga, E.J. Myas, W. Verstraete and R. L. Wentworth (Eds). Elsevier Biomedical Press, Amsterdam, New York. 1982. 436 pp. Price: US$80·00 (Dfl. 172·00)