Dyfyniad APA

Percentage Distribution of 6- to 12-year-olds, 1972-97. US Department of Education.

Dyfyniad Arddull Chicago

Percentage Distribution of 6- to 12-year-olds, 1972-97. US Department of Education.

Dyfyniad MLA

Percentage Distribution of 6- to 12-year-olds, 1972-97. US Department of Education.

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