Raphaël Levy, The astrological works of Abraham Ibn Ezra. A literary and linguistic study with special reference to the old French translation of Hagin, The John Hopkins studies in Romance literatures and languages, 8, Baltimore, 1927
CR Brunel in Le Moyen Age 37 (1927) p.343 ; CR Fouché in Revue des langues romanes 65 (1927) p.128