J J O’Connor and E F Robertson. «Madhava of Sangamagrama». School of Mathematics and Statistics University of St Andrews, Scotland. Arkivert fra originalen 14. mai 2006. Besøkt 8. september 2007.
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J J O’Connor and E F Robertson. «Madhava of Sangamagrama». School of Mathematics and Statistics University of St Andrews, Scotland. Arkivert fra originalen 14. mai 2006. Besøkt 8. september 2007.