Gaya APA

Frondel, C. (1920). The Sistem of Mineralogy Vol.III, Silica Minerals, 7th-Edition . : John Wiley & Sons, Inc..

Gaya MLA

Frondel, Clifford. "The Sistem of Mineralogy Vol.III, Silica Minerals, 7th-Edition". : John Wiley & Sons, Inc., 1920. Text.