Παραπομπή APA

Smith, F. (1971). Conservation in the United states: A documentary history. 5v. Van nostrand.

Παραπομπή Chicago Style

Smith, Frank. Conservation in the United States: A Documentary History. 5v. New york: Van nostrand, 1971.

Παραπομπή MLA

Smith, Frank. Conservation in the United States: A Documentary History. 5v. Van nostrand, 1971.