APA

United States, . (1969). U.S. airworthiness certificates & authorizations for operation ... aircraft. [Washington, D.C: .

Chicago

United States, . 1969. U.S. airworthiness certificates & authorizations for operation ... aircraft. [Washington, D.C: .

Harvard

United States, . (1969). U.S. airworthiness certificates & authorizations for operation ... aircraft. [Washington, D.C: .

MLA

United States, . U.S. airworthiness certificates & authorizations for operation ... aircraft. [Washington, D.C: . 1969.