1. Ueber die Einwirkung des Ammoniaks auf Glyoxal;Debus;Justus Liebigs Ann. Chem.,1858
2. P.L. Warner, E.J. Luber, Jr. Westwood Pharmaceuticals, Inc., USA (1980) US4191767A 27 p. Cont.-in-part of U.S. Ser. No. 757.640, https://www.google.com/patents/US4191767.
3. J.L. Adams, R.S. Garigipati, J.C. Boehm, Smithkline Beecham Corporation, USA (1997) US5670527A 39 p. Cont.-in-part of U.S. Ser. No. 369.964 https://www.google.com/patents/US5670527.
4. C. Almansa Rosales, C. Gonzalez, M.C. Torres Barreda, Uriach & Cia S.A., Spain (2001) WO2001070704A1 43 p. https://www.google.com/patents/WO2001070704A1?cl=ko.
5. Synthesis and action of 1-n-hexyl-2-phenyl-3-(n-alkoxymethyl)- and 1-n-hexyl-2-phenyl-3-(n-alkylthiomethyl) imidazolium chlorides;Pernak;Pharmazie,1990