Lott; Smith; Christiansen Journal of the American Pharmaceutical Association (1912-1977), vol. 26, p. 203 Chem. Zentralbl., 1937 , vol. 108, # II p. 3153 Full Text Show Details Squibb and Sons Patent: US2146752 , 1936 ; Full Text Show Details Squibb and Sons Patent: US2013662 , 1934 ; Full Text Show Details Squibb and Sons Patent: US2136387 , 1936 ;