APA

National Education Association of the United States. Deot. of Elementary School Principals, . (1948). The elementary school principalship-today and tomorrow. Washington: The National Elementary Principal.

Chicago

National Education Association of the United States. Deot. of Elementary School Principals, . 1948. The elementary school principalship-today and tomorrow. Washington: The National Elementary Principal.

Harvard

National Education Association of the United States. Deot. of Elementary School Principals, . (1948). The elementary school principalship-today and tomorrow. Washington: The National Elementary Principal.

MLA

National Education Association of the United States. Deot. of Elementary School Principals, . The elementary school principalship-today and tomorrow. Washington: The National Elementary Principal. 1948.