Παραπομπή APA

Elwell, D. (1979). Man made gemstones. John Wiley.

Παραπομπή Chicago Style

Elwell, D. Man Made Gemstones. New York: John Wiley, 1979.

Παραπομπή MLA

Elwell, D. Man Made Gemstones. John Wiley, 1979.