Dyfyniad APA
Petersen, R. A. (1991). Health issues for secondary teachers. Kendall/Hunt.
Dyfyniad Arddull Chicago
Petersen, Ray A. Health Issues for Secondary Teachers. Dbuque, Iowa: Kendall/Hunt, 1991.
Dyfyniad MLA
Petersen, Ray A. Health Issues for Secondary Teachers. Kendall/Hunt, 1991.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.