Percentage Distribution of 6- to 12-year-olds, 1972-97. US Department of Education.
Чикаго-гийн эшлэл (17 дахь хэвлэлт)Percentage Distribution of 6- to 12-year-olds, 1972-97. US Department of Education.
MLA -ийн эшлэл (9 дэх хэвлэлт)Percentage Distribution of 6- to 12-year-olds, 1972-97. US Department of Education.
Анхааруулга: Эдгээр ишлэлүүд үргэлж 100% үнэн зөв биш байж магадгүй.