Feltwell, J. (1993). The encyclopedia of butterflies. Prentice Hall General Reference.
Cita Chicago (17th ed.)Feltwell, John. The Encyclopedia of Butterflies. New York: Prentice Hall General Reference, 1993.
Cita MLA (9th ed.)Feltwell, John. The Encyclopedia of Butterflies. Prentice Hall General Reference, 1993.
Atenció: Aquestes cites poden no estar 100% correctes.