The Rubaiyat of Omar Khayyam was originally written in Persian by the Persian poet Omar Khayyam.

Rubaiyat is a book written by Omar Khayyam in the medievel period in the Arabic region and "Rubaiyat" is the tittle given to that book.

Quatrians; as, the Rubaiyat of Omar Khayyam. Sometimes in pl. construed as sing., a poem in such stanzas.

Quatrians; as, the Rubaiyat of Omar Khayyam. Sometimes in pl. construed as sing., a poem in such stanzas.

Yes, "The Kite Runner" by Khaled Hosseini does make a reference to the Rubaiyat of Omar Khayyam. In the novel, Baba quotes lines from the Rubaiyat in Farsi when discussing the importance of being true to oneself and one's values.