Gaya APA

Simkin, T. et al (1981). Volcanoes of the world : a regional directory, gazetteer, and chronology of vulcanism during the last 10,000 years . Pennsylvania: Hutchinson Ross.

Gaya MLA

Simkin, Tom. et al. "Volcanoes of the world : a regional directory, gazetteer, and chronology of vulcanism during the last 10,000 years". Pennsylvania: Hutchinson Ross, 1981. Text.