Percentage Distribution of 6- to 12-year-olds, 1972-97. US Department of Education.
Chicagoスタイル(17版)引用形式Percentage Distribution of 6- to 12-year-olds, 1972-97. US Department of Education.
MLA(9版)引用形式Percentage Distribution of 6- to 12-year-olds, 1972-97. US Department of Education.
警告: この引用は必ずしも正確ではありません.