Hoffmann-La Roche Patent: DE703227 , 1934 ; Fortschr. Teerfarbenfabr. Verw. Industriezweige, vol. 25, p. 421 Full Text Show Details Hoffmann-La Roche Patent: CH174080 , 1934 ; Full Text Show Details Sumiki; Mitsunaga J. agric.chem. Soc.Chem.Abstr., 1951 , vol. 25, p. 198 J. agric.chem. Soc.Chem.Abstr., 1953 , p. 10643 Full Text Show Details Hoffmann-La Roche Patent: US2039929 , 1935 ;