Dyfyniad APA

kaufman, J. (2013). The first 20 hours: How to learn anything fast. Portfolio Penguin.

Dyfyniad Arddull Chicago

kaufman, Josh. The First 20 Hours: How to Learn Anything Fast. London: Portfolio Penguin, 2013.

Dyfyniad MLA

kaufman, Josh. The First 20 Hours: How to Learn Anything Fast. Portfolio Penguin, 2013.

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