Dyfyniad APA
Wells, W. (2009). Apocalypse When?: Calculating How Long the Human Race Will Survive. Praxis. https://doi.org/10.1007/978-0-387-09837-1
Dyfyniad Arddull Chicago
Wells, Willard. Apocalypse When?: Calculating How Long the Human Race Will Survive. New York, NY: Praxis, 2009. https://doi.org/10.1007/978-0-387-09837-1.
Dyfyniad MLA
Wells, Willard. Apocalypse When?: Calculating How Long the Human Race Will Survive. Praxis, 2009. https://doi.org/10.1007/978-0-387-09837-1.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.