Cite
MLA (8th Edition)
U.S. Geological Survey Professional Paper, No. 1220-1227. U.S. G.P.O, 1981.
APA (7th Edition)
U.S. Geological Survey professional paper, no. 1220-1227. (1981). U.S. G.P.O.
Chicago (17th Edition)
U.S. Geological Survey Professional Paper, No. 1220-1227. Washington: U.S. G.P.O, 1981.