(Ingelesez)Willcox, Michael. (2000). «Soap»Poucher's Perfumes, Cosmetics and Soaps. Hilda Butler, 453 or. ISBN978-0-7514-0479-1. jatorrizkotik artxibatua (artxibatze data: 2016-08-20) Aipua: «The earliest recorded evidence of the production of soap-like materials dates back to around 2800 BCE in ancient Babylon.».