1. Eber’s Papyrus, cited from Pierce, H. B.;J. Biol. Chem.,1932
2. THE USE OF BAKERS' YEAST IN DISEASES OF THE SKIN AND OF THE GASTRO-INTESTINAL TRACT
3. Avicenna—Canons—Book 2 on Simples, Bulag. Edition of 1877, Cairo, Egypt. p. 461
4. Ibn El—Beithar. Traité des Simples, Tome 2, in Notices et Extraits des Manuscrits de la Bibliothèque Nationale, Tome 25, Paris 1881, p. 45
5. Daoud el Antaki, Tadkira, Cairo, Egypt, 1308 A. H. (about 1890) p. 127, vol. 1