GILBERTSON, D. (1989). Practical Ecology For Geography And Biology. Croom Helm.
Lua i Stíl Chicago (17ú heag.)GILBERTSON, DD. Practical Ecology For Geography And Biology. Croom Helm, 1989.
Lua MLA (8ú heag.)GILBERTSON, DD. Practical Ecology For Geography And Biology. Croom Helm, 1989.
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