"CRD - Enforcement - Products Containing Azadirachtin (also known as Neem Oil)". webarchive.nationalarchives.gov.uk. Retrieved 4 July 2017. ↑ Robert L. Metcalf (2007), "Insect Control", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, pp. 1–64, doi:10.1002/14356007.a14_263 ↑ "Neem Oil Monograph". Drugs.com.