- Billroth's operation I. Online Medical Dictionary. Centre for Cancer Education, University of Newcastle upon Tyne. URL: http://cancerweb.ncl.ac.uk/cgi-bin/omd?Billroth's+operation+I. Accessed on: June 15, 2008.
- Billroth's operation I. whonamedit.com. http://www.whonamedit.com/synd.cfm/2730.html. Accessed on: June 15, 2008.
- Schematic of Billroth I & II - thefreedictionary.com.