Não informado. (1967). Educational television international. Centre for Educational Television Overseas.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Educational Television International. London: Centre for Educational Television Overseas, 1967.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Educational Television International. Centre for Educational Television Overseas, 1967.
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