United Gas Improv.Co. Patent: US2376396 , 1941 ; Full Text Show Details United Gas Improv.Co. Patent: US2246545 , 1938 ; Full Text Show Details United Gas Improv.Co. Patent: US2246546 , 1939 ; Full Text Show Details United Gas Improv.Co. Patent: US2246547 , 1940 ; Full Text Show Details Jones; Chorley Journal of the Chemical Society, 1946 , p. 832 Full Text Show Details United Gas Improv.Co. Patent: US2382031 , 1942 ; Full Text Show Details Ultee Journal of the Chemical Society, 1948 , p. 530 Recueil des Travaux Chimiques des Pays-Bas, 1949 , vol. 68, p. 129,130