Robertson, R. (1961). Mineral use guide. Cleaver-Hume.
Chicago Edition CitationRobertson, R.H.S. Mineral Use Guide. London: Cleaver-Hume, 1961.
Cita MLARobertson, R.H.S. Mineral Use Guide. Cleaver-Hume, 1961.
Atenció: Aquestes cites poden no estar 100% correctes.