Não informado. (1971). Educational broadcasting international. Centre for Educational Television Overseas.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Educational Broadcasting International. London: Centre for Educational Television Overseas, 1971.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Educational Broadcasting International. Centre for Educational Television Overseas, 1971.
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