APA (7th ed.) Citation

Webster, R. (1940). Practical gemmology: A study of the identification of gem-stones, pearls, and ornamental minerals. N.A.G. Press, ltd..

Chicago Style (17th ed.) Citation

Webster, Robert. Practical Gemmology: A Study of the Identification of Gem-stones, Pearls, and Ornamental Minerals. London: N.A.G. Press, ltd., 1940.

MLA (9th ed.) Citation

Webster, Robert. Practical Gemmology: A Study of the Identification of Gem-stones, Pearls, and Ornamental Minerals. N.A.G. Press, ltd., 1940.