Selected methods for the detection and assessment of ecological effects resulting from the release of genetically engineered micro-organisms to the terrestrial environment: Stotzky G., Broder M.W., Doyle J.D. and Jones R.A. Laboratory of Microbial Ecology, Department of Biology, New York University, New York, NY 10003, USA. Adv. Appl. Microbiol., 1993 38 1–98. Summ. in Engl.