Geological Survey (U.S.). (1925). Standard symbols adopted by Board of Surveys and Maps, U.S.A. [publisher not identified].
Chicago Style (17th ed.) CitationGeological Survey (U.S.). Standard Symbols Adopted by Board of Surveys and Maps, U.S.A. Washington: [publisher not identified], 1925.
MLA (9th ed.) CitationGeological Survey (U.S.). Standard Symbols Adopted by Board of Surveys and Maps, U.S.A. [publisher not identified], 1925.
Warning: These citations may not always be 100% accurate.