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Ian G. Pearce: Early Indian culture – Indus civilisation. [w:] Indian Mathematics: Redressing the balance [on-line]. School of Mathematical and Computational Sciences University of St Andrews, 2002. [dostęp 2006-05-06]. [zarchiwizowane z tego adresu (2008-12-28)].
Ian G. Pearce: Early Indian culture – Indus civilisation. [w:] Indian Mathematics: Redressing the balance [on-line]. School of Mathematical and Computational Sciences University of St Andrews, 2002. [dostęp 2006-05-06]. [zarchiwizowane z tego adresu (2008-12-28)].