“Omar Khayyam: the problem solver” (英語). gulfnews.com. Al Nisr Publishing (2013年8月15日). 2024年9月13日閲覧。 “When Seljuq Turkish tribes invaded southwestern Asia in the 11th Century, encompassing Mesopotamia, Syria, Palestine and most of Iran, few could withstand the onslaught. In 1038, the Seljuq ruler Toghrïl proclaimed himself sultan at Nishapur, and occupied Baghdad in 1055. Khayyam grew up in this military empire, though he also managed to study under renowned scholars such as Shaikh Mohammad Mansouri and Imam Muwaffaq Nishapuri. A workaholic Omar Khayyam was soon splitting his days into three: by day he taught algebra and geometry, attended the Seljuq court as an adviser of Malek-Shah in the evening, and returned to his astronomy books at night to complete his Jalali calendar.”
