1. Marcus Porcius Censorius Cato, “De Agriculture,” 184 B.C., “Scriptores rei Rustica.”
2. Abu Mansur Muwaffak, of Hirow, North Persia (975 A.D.). Translation in Vol. III of Kobert's “Historische Studien,” Halle (1893) as quoted by R. P. Walton, in “A Comprehensive Survey of Starch Chemistry,” Chemical Catalog Co., New York, 1928, Part 1, p. 236.
3. A. van Leeuwenhoek “Epistolae Physiologicae super compluribus Naturae Arcanus,” Epistolae XXVI, 1719.
4. “Universal Lexikon des Gegenwart vergangenheit,” H. A. Pierer, ed., Altenburg, Germany, Vol. 1, 1733; Vol. 15, 1737; Vol. 39, 1744.