National Association of Elementary School Principals (U.S.). (1980). Principal. National Association of Elementary School Principals.
Чикаго-гийн эшлэл (17 дахь хэвлэлт)National Association of Elementary School Principals (U.S.). Principal. Arlington, Va.: National Association of Elementary School Principals, 1980.
MLA -ийн эшлэл (9 дэх хэвлэлт)National Association of Elementary School Principals (U.S.). Principal. National Association of Elementary School Principals, 1980.
Анхааруулга: Эдгээр ишлэлүүд үргэлж 100% үнэн зөв биш байж магадгүй.