APA aipamena

(2000). Percentage Distribution of 6- to 12-year-olds, 1972-97. U.S. Department of Education.

Chicago Style aipamena

Percentage Distribution of 6- to 12-year-olds, 1972-97. U.S. Department of Education, 2000.

MLA aipamena

Percentage Distribution of 6- to 12-year-olds, 1972-97. U.S. Department of Education, 2000.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.