Buschmann H., Christoph T., Friderichs E., Maul C., Sundermann B. Analgesics from Chemistry and Pharmacology to Clinical Application. - 2002. - pp. 217
Kleemann A. Pharmaceutical Substances. - 2000. - pp. 1586-1587
The Merck Index. - 15th ed. - Royal Society of Chemistry, 2013. - pp. 1324