Gaya APA

Hawley, M, E, (. (1976). Coal, part 2 : scientific and technical aspects. (1976). : Dowden : Hutchinson & Ross, Inc.,.

Gaya MLA

Hawley, Mones, E., (ed). "Coal, part 2 : scientific and technical aspects.". 1976 : Dowden : Hutchinson & Ross, Inc.,, 1976. Text.