– Isaac, Erich, Influence of religion on the spread of citrus: The religious practices of the Jews helped effect the introduction of citrus to Mediterranean lands, Science Magazine, #129, published in January 1959.
– Binyamin da Tudela, Libro dei viaggi (Sefer massa’ot),a cura di Laura Minervini, Palermo, Flaccovio 1989, page 132.
– Colafemmina, C., Hebrew Inscriptions of the Early Medieval Period in Southern Italy, in The Jews of Italy, Memory and Identity, pp. 65-81
– Freimann, A., Jewish Scribes in Medieval Italy, Alexander Marx Jubilee Volume, New York, 1950, pp. 248-321