Kogel, J. E., & Kogel, J. E. (2006). Industrial minerals & rocks: Commodities, markets, and uses (7th ed.). Littleton, CO.: Society for Mining, Metallurgy, and Exploration.
Παραπομπή Chicago StyleKogel, Jessica Elzea, and Jessica Elzea Kogel. Industrial Minerals & Rocks: Commodities, Markets, and Uses. 7th ed. Littleton, CO.: Society for Mining, Metallurgy, and Exploration, 2006.
Παραπομπή MLAKogel, Jessica Elzea, and Jessica Elzea Kogel. Industrial Minerals & Rocks: Commodities, Markets, and Uses. 7th ed. Littleton, CO.: Society for Mining, Metallurgy, and Exploration, 2006.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.