1. Council of Europe (1974). Natural Flavouring Substances. Their Sources, and Added Artificial Flavouring Substances. Partial Agreement in the Social and Public Health Field. List N(1). Series 1 (b). no. 339. p. 90. Strasbourg.
2. Epstein, W. L. (1975). Report to RIFM, 6 May.
3. Flavoring Extract Manufacturers' Association (1965). Survey of flavoring ingredient usage levels. No. 2909. Fd Technol., Champaign 19 (2), part 2. 155.
4. Food Chemicals Codex (1972). 2nd Ed. Prepared by the Committee on Specifications. Food Chemicals Codex, of the Committee on Food Protection. p. 619. National Academy of Sciences–National Research Council Publ. 1406. Washington, D.C.