Dyfyniad APA

Harari, Y. N. (2019). 21 lessons for the 21st century. Vintage.

Dyfyniad Arddull Chicago

Harari, Yuval N. 21 Lessons for the 21st Century. London: Vintage, 2019.

Dyfyniad MLA

Harari, Yuval N. 21 Lessons for the 21st Century. Vintage, 2019.

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