Shell Devel.Co. Patent: US1938180 , 1931 ; Full Text Show Details Rochow; Dennis Journal of the American Chemical Society, 1935 , vol. 57, p. 486 Full Text View citing articles Show Details Groll Journal of the American Chemical Society, 1930 , vol. 52, p. 2998,3000 Full Text Show Details Shell Devel.Co. Patent: US1938179 , 1930 ;