. . . . "2,4-Dihydroxybenzoic Acid"@en . . . . . . . . . . "Peter Neumann, Ulrich Eichenauer, \"Preparation of 2,4-dihydroxybenzoic acid.\" U.S. Patent US4996354, issued August, 1955."@en . . . . . "89-86-1"@en . "experimental"@en . . . . . . . . . . . . . . . . . . . . .