Evans; Edlund Industrial and Engineering Chemistry, 1936 , vol. 28, p. 1188 Show Details Shell Devel.Co. Patent: US1968033 , 1931 ; Full Text Show Details N.V. de Bataafsche Petr.Mij. Patent: DE629601 , 1932 ; Fortschr. Teerfarbenfabr. Verw. Industriezweige, vol. 23, p. 106