Schipp, Bernhard; Krämer, Walter (2008): Statistical Inference, Econometric Analysis and Matrix Algebra: Festschrift in Honour of Götz Trenkler, Springer, 387. orrialdea. ISBN 9783790821208
Lumpkin, Beatrice; Strong, Dorothy (1995): Multicultural science and math connections: middle school projects and activities, Walch Publishing, 118. orrialdea. ISBN 9780825126598
Bulliet, Richard; Crossley, Pamela; Headrick, Daniel; Hirsch, Steven; Johnson, Lyman (2010): The Earth and Its Peoples: A Global History, Volume 1, Cengage Learning, 192. orrialdea. ISBN 1439084742 «Indian mathematicians invented the concept of zero and developed the "Arabic" numerals and system of place-value notation used in most parts of the world today»
