«Khaqani, Afdal al-Din Ibrahim: eccezionale poeta persiano di Shirwan; 1126-1199. È noto per aver creato un nuovo tipo di qasida * per i suoi panegirici, ma soprattutto per la sua ascetica poesia sufi.»
^Robert T. Lambdin, Laura C. Lambdin, Encyclopedia of Medieval Literature, Greenwood Publishing Group, 2000. pg 134: "The Twelfth century Persian Khaqani Sharvani wrote a poem entitled "The Language of the Birds" apparently related to the better-known work of his Persian contemporary Farid Ud-Din Attar, the Conference of the Birds
^Reinert, B. "Ḵh̲āḳānī , afḍal al-dīn ibrāhīm (Badīl) b. ʿalī b. ʿut̲h̲mān." Encyclopaedia of Islam, Second Edition. Edited by: P. Bearman, Th. Bianquis , C.E. Bosworth , E. van Donzel and W.P. Heinrichs. Brill, 2009. Brill Online. Excerpt: ", outstanding Persian poet, born about 520/1126, d. 595/1199, who left a diwan , the mathnawi called Tuhfat al-Irāqayn and sixty letters. "
^Anna Livia Beelaert, "Khaqani Sherwani" in Encyclopedia Iranica: "ḴĀQĀNI ŠERVĀNI (or Šarvāni), AFŻAL-AL-DIN BADIL B. ʿALI B. ʿOṮMĀN, a major Persian poet and prose writer (b. Šervān, ca. 521/1127; d. Tabriz, between 582/1186-87 and 595/1199). " [1][2]
^Annemarie Schimmel, Burzine K. Waghmar , The empire of the great Mughals: history, art and culture, Reaktion Books, 2004. pg 260: "The poet call this portrayal 'Fragrant Bouquet,' Dastanbu, a word user by the Persian poet Khaqani (died 1199) in a poem of praise to spouse of his patron"
^Lloyd V. J. Ridgeon, Islamic interpretations of Christianity, Palgrave Macmillan, 2001. pg 123: "Quatrain attributed to the Persian poet Khaqani (d. 1200)
^Khaqani in Encyclopedia Britannica:"Persian poet, whose importance rests mainly on his brilliant court poems, satires, and epigrams."
^Jan Rypka, History of Iranian Literature. Reidel Publishing Company. 1968. pp 203-208.