Analysis of information sources in references of the Wikipedia article "Omar Khayyám" in Vietnamese language version.
Later, al-Karkhi, Ibn-Tahir and the great Ibn al-Haytham in the tenth/eleventh century took it further by considering cubic and quartic equations, followed by the Persian mathematician and poet Omar Khayyam in the eleventh century
However, Khayyam himself seems to have been the first to conceive a general theory of cubic equations.
