↑ William Darrach Halsey, Emanuel Friedman (1983). Collier's Encyclopedia, with bibliography and index. When the Arabian empire was expanding and contact was made with India, the Hindu numeral system and the early algorithms were adopted by the Arabs
↑ Brezina, Corona (2006), Al-Khwarizmi: The Inventor of Algebra, The Rosen Publishing Group, tr. 39–40, ISBN978-1-4042-0513-0: "Historians have speculated on al-Khwarizmi's native language. Since he was born in a former Persian province, he may have spoken the Persian language. It is also possible that he spoke Khwarezmian, a language of the region that is now extinct."
