Gaya APA

Schumann, W. (1997). Gemstones of the world, rev. & expanded ed. Transl. by Annette Englander. : Edelsteine und Schmucksteine. 1995 . London: London NAG Press.

Gaya MLA

Schumann, Walter. "Gemstones of the world, rev. & expanded ed. Transl. by Annette Englander. : Edelsteine und Schmucksteine. 1995 ". London: London NAG Press, 1997. Buku.