Cita APA (7a ed.)

Schumann, W. (1997). Gemstones of the world (Rev. & expanded ed.). Sterling Pub.

Cita Chicago Style (17a ed.)

Schumann, Walter. Gemstones of the World. Rev. & expanded ed. New York: Sterling Pub, 1997.

Cita MLA (9a ed.)

Schumann, Walter. Gemstones of the World. Rev. & expanded ed. Sterling Pub, 1997.