APA

United States, . (1977). Continuing need for improved operation & maintenance of municipal waste treatment plants. [Washington, D.C: .

Chicago

United States, . 1977. Continuing need for improved operation & maintenance of municipal waste treatment plants. [Washington, D.C: .

Harvard

United States, . (1977). Continuing need for improved operation & maintenance of municipal waste treatment plants. [Washington, D.C: .

MLA

United States, . Continuing need for improved operation & maintenance of municipal waste treatment plants. [Washington, D.C: . 1977.