Mahmud, S. (1985). A Text Book of Higher Trigonometry (5th ed.). The Ideal Library.
Chicago-viite (17. p.)Mahmud, Sultan. A Text Book of Higher Trigonometry. 5th ed. Dhaka: The Ideal Library, 1985.
MLA-viite (9. p.)Mahmud, Sultan. A Text Book of Higher Trigonometry. 5th ed. The Ideal Library, 1985.
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