Bruijn, J.T.P de
Mystical epigrams. J.T.P. de Bruijn.
In: Persian Sufi poetry. An introduction to the mystical use of classical Persian poems. J.T.P. de Bruijn. Richmond, Curzon, 1997. (Curzon Sufi series).
Bevat paragraaf "The case of Umar-i Khayyám'", p. 9-13