1. www.fda.gov/RegulatoryInformation/LawsEnforcedbyFDA/FederalFoodDrugandCosmeticActFDCAct/default.htm
2. Determination that PITRESSIN TANNAGE IN OIL (vasopressin tannage) injection, 5 pressor units/milliliter, was not nithdrawn from sale for reasons of safety or effectiveness;Food and Drug Administration;Fed Regist,2012
3. www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/EnforcementActivitiesbyFDA/SelectedEnforcementActionsonUnapprovedDrugs/ucm118990.htm
4. The FDA unapproved drugs initiative: An observational study of the consequences for drug prices and shortages in the United States;Gupta;J Manag Care Spec Pharm,2017
5. www.parpharm.com/about/