. . . . . . . . . . . . . . . . . . . . . . . . . "George E. Kuhlmann, Alan G. Bemis, \"Preparation of phthalic acid by solventless oxidation of liquid ortho-xylene.\" U.S. Patent US4299977, issued November, 1975."@en . . . . . "experimental"@en . . . "Ortho-Xylene"@en . .