Dyfyniad APA

Freedman, D., & Pisani, R. P. (2006). Statistics (3rd ed.). Viva Books.

Dyfyniad Arddull Chicago

Freedman, David, and Robert Purves Pisani. Statistics. 3rd ed. New Delhi: Viva Books, 2006.

Dyfyniad MLA

Freedman, David, and Robert Purves Pisani. Statistics. 3rd ed. Viva Books, 2006.

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