APA
United Nations G. O. . E. C. F. E., United Nations G. O. . E. C. F. E., . (1991). Assessment of long-range transboundary air polluti. New York: United Nation U S A.
Chicago
United Nations Government Of Economic Commission For Europe, United Nations Government Of Economic Commission For Europe, . 1991. Assessment of long-range transboundary air polluti. New York: United Nation U S A.
Harvard
United Nations G. O. . E. C. F. E., United Nations G. O. . E. C. F. E., . (1991). Assessment of long-range transboundary air polluti. New York: United Nation U S A.
MLA
United Nations Government Of Economic Commission For Europe, United Nations Government Of Economic Commission For Europe, . Assessment of long-range transboundary air polluti. New York: United Nation U S A. 1991.
