1. Furukawa, T.; “Cost Down Plan on Liquid Purification Method (in Japan),” Plant & Process, 40, 32–43 (1998)
2. Hearth; http://www.heart-and-earth.com/soap_contents_oil_fatty_acid_value.html (2009)
3. Hobbs, P. V.; ICE PHYSICS, pp. 580–581, Clarendon Press, Oxford, UK (1974)
4. Japan Oil Chemists' Society ed.; The Handbook of Oil Chemistry, 4th ed., p. 192–206, 258–265, Maruzen, Tokyo, Japan (2001)
5. Kagaku Kogaku Kyokai ed.; Chemical Engineering Handbook, 5th ed. (Kagaku Kogaku Benran, 5th ed.), p. 753–757, Maruzen, Tokyo, Japan (1988)