@book{158896, author = {Ravera, O. (Oscar) and European Ecological Symposium (5th : 1989 : Sienna, Italy)}, title = {Terrestrial and aquatic ecosystems : perturbation and recovery /}, publisher = {Ellis Horwood,}, year = {1991}, series = {Ellis Horwood series in environmental management, science and technology}, address = {New York :} }