Gaya APA

Lyons, P., Alpern, B. (1989). Coal: Clasification, Coalification, Mineralogy, Trace. Element Chemistry and Oil Gas Patentional. . Amsterdam: Elsevier.

Gaya MLA

Lyons, P.C., Alpern, B.. "Coal: Clasification, Coalification, Mineralogy, Trace. Element Chemistry and Oil Gas Patentional.". Amsterdam: Elsevier, 1989. Text.