Gaya APA

Ostroumov, A, Y, S. (1991). Concervation of living nature and resources : problem ,trends ,and prospeets . Newyork: Springer-Verlag.

Gaya MLA

Ostroumov, A.V., Yablokov, S.A.. "Concervation of living nature and resources : problem ,trends ,and prospeets". Newyork: Springer-Verlag, 1991. Text.