Guinness (Firm). (1991). Guiness world records 1991. Bantam Books.
Cita Chicago (17th ed.)Guinness (Firm). Guiness World Records 1991. New York: Bantam Books, 1991.
Cita MLA (9th ed.)Guinness (Firm). Guiness World Records 1991. Bantam Books, 1991.
Atenció: Aquestes cites poden no estar 100% correctes.