Dyfyniad APA

Weisman, A. (2013). Countdown: Our Last, Best Hope for a future on earth? Little Brown.

Dyfyniad Arddull Chicago

Weisman, Alan. Countdown: Our Last, Best Hope for a Future on Earth? London: Little Brown, 2013.

Dyfyniad MLA

Weisman, Alan. Countdown: Our Last, Best Hope for a Future on Earth? Little Brown, 2013.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.