Roberts, W. L., Rapp, G. R., & Weber, J. (1974). Encyclopedia of minerals. Van Nostrand Reinhold Co.
Dyfyniad Arddull ChicagoRoberts, Willard Lincoln, George Robert Rapp, and Julius Weber. Encyclopedia of Minerals. New York: Van Nostrand Reinhold Co, 1974.
Dyfyniad MLARoberts, Willard Lincoln, et al. Encyclopedia of Minerals. Van Nostrand Reinhold Co, 1974.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.