APA
(1971). Environmental control seminar proceedings, Rotterdam, Warsaw, Bucharest, May 25-June 4, 1971. Washington: Bureau of International Commerce; for sale by the Supt. of Docs., U.S. Govt. Print. Off.
Chicago
1971. Environmental control seminar proceedings, Rotterdam, Warsaw, Bucharest, May 25-June 4, 1971. Washington: Bureau of International Commerce; for sale by the Supt. of Docs., U.S. Govt. Print. Off.
Harvard
(1971). Environmental control seminar proceedings, Rotterdam, Warsaw, Bucharest, May 25-June 4, 1971. Washington: Bureau of International Commerce; for sale by the Supt. of Docs., U.S. Govt. Print. Off.
MLA
Environmental control seminar proceedings, Rotterdam, Warsaw, Bucharest, May 25-June 4, 1971. Washington: Bureau of International Commerce; for sale by the Supt. of Docs., U.S. Govt. Print. Off. 1971.