Brown, L. R. (1972). World without Borders. Random House.
Cita Chicago (17th ed.)Brown, Lester R. World Without Borders. New York: Random House, 1972.
Cita MLA (9th ed.)Brown, Lester R. World Without Borders. Random House, 1972.
Atenció: Aquestes cites poden no estar 100% correctes.