O'Connor, J.J. and E.F. Robertson. 2000. 'Indian Numerals'Diarsipkan 2007-09-29 di Wayback Machine., MacTutor History of Mathematics Archive, School of Mathematics and Statistics, University of St. Andrews, Scotland.
O'Connor, J.J. and E.F. Robertson. 2000. 'Indian Numerals'Diarsipkan 2007-09-29 di Wayback Machine., MacTutor History of Mathematics Archive, School of Mathematics and Statistics, University of St. Andrews, Scotland.