Dyfyniad APA

Yale University. School of Medicine. Dept. pf Public Health. Contributions. s. l.

Dyfyniad Arddull Chicago

Yale University. School of Medicine. Dept. pf Public Health. Contributions. New Haven: s. l.

Dyfyniad MLA

Yale University. School of Medicine. Dept. pf Public Health. Contributions. s. l.

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