^Bo Utas, Tariq ut-tahqiq. A Sufi Mathnavi ascribed to Hakim Sana’i of Ghazna and probably composed by Ahmad b. al-Hasan b. Muhammad an-Naxcavani. A critical edition, with a history of the text and a commentary (Scandinavian Institute of Asian Studies Monograph Series, 13), Lund 1973. 243, 55 pp.
^Bo Utas, A Persian Sufi Poem: Vocabulary and Terminology. Scandinavian Institute of Asian Studies Monograph Series, Curzon Press, 1977.