ASSOCIATION, N. E. Educational leadership: Progress and possibilities, eleventh yearbook. The National Education Association.
Παραπομπή σε μορφή Chicago (17η εκδ.)ASSOCIATION, NATIONAL EDUCATION. Educational Leadership: Progress and Possibilities, Eleventh Yearbook. The National Education Association.
Παραπομπή σε μορφή MLA (8th εκδ.)ASSOCIATION, NATIONAL EDUCATION. Educational Leadership: Progress and Possibilities, Eleventh Yearbook. The National Education Association.
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