Παραπομπή APA

Hellawell, J. (1986). Biological Indicaors of Freshwater Pollution and Environmental Management. Elsevier Applied Science.

Παραπομπή Chicago Style

Hellawell, J.M. Biological Indicaors of Freshwater Pollution and Environmental Management. London: Elsevier Applied Science, 1986.

Παραπομπή MLA

Hellawell, J.M. Biological Indicaors of Freshwater Pollution and Environmental Management. Elsevier Applied Science, 1986.