Cita APA (7th ed.)
Sivard, R. L. (1981). World energy survey (2nd ed.). World Priorities.
Cita Chicago (17th ed.)
Sivard, Ruth Leger. World Energy Survey. 2nd ed. Leesburg, Virginia: World Priorities, 1981.
Cita MLA (9th ed.)
Sivard, Ruth Leger. World Energy Survey. 2nd ed. World Priorities, 1981.
Atenció: Aquestes cites poden no estar 100% correctes.