United States. Department of the Interior. Office of the Solicitor & United States. Department of the Interior. Division of Information and Library Services. Law Branch. (1981). Unpublished M-opinions of the Solicitor, U.S. Department of the Interior. [Department of the Interior].
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)United States. Department of the Interior. Office of the Solicitor và United States. Department of the Interior. Division of Information and Library Services. Law Branch. Unpublished M-opinions of the Solicitor, U.S. Department of the Interior. [Washington, D.C.]: [Department of the Interior], 1981.
Trích dẫn kiểu MLA (xuất bản lần thứ 8)United States. Department of the Interior. Office of the Solicitor và United States. Department of the Interior. Division of Information and Library Services. Law Branch. Unpublished M-opinions of the Solicitor, U.S. Department of the Interior. [Department of the Interior], 1981.