^Kasich AM, Fein HD (January 1958). "Hexocyclium methosulfate in active duodenal ulcer; evaluation of a new anticholinergic drug in conventional and long-acting forms, especially its effect on gastric pH as studied in 48-hour analysis". The American Journal of Digestive Diseases. 3 (1): 12–23. doi:10.1007/BF02231305. PMID13487546.