Cite
MLA (8th Edition)
Organization of Petroleum Exporting Countries (OPEC), 1973. Maps.com, 1999.
APA (7th Edition)
Organization of Petroleum Exporting Countries (OPEC), 1973. (1999). Maps.com.
Chicago (17th Edition)
“Organization of Petroleum Exporting Countries (OPEC), 1973.” Place of publication not identified: Maps.com, 1999.