MedlinePlus: Belladonna Alkaloid Combinations and Phenobarbital
- Provides information about dosage, usage, warnings, and side effects.
- http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a601024.html

Donnatal Extentabs - PBM Pharmaceuticals
- Official Pharmaceutical Website with information for consumers and health professionals.
- http://www.donnatal.com/

Donnatal
- Full prescribing information from RxList.
- http://www.rxlist.com/cgi/generic3/bellapb.htm