. . . . . . . . . "Isobutyric Acid"@en . . . "79-31-2"@en . . . "experimental"@en . . . . . . . . . . . . . "Richard V. Norton, Lee R. Zehner, Ralph F. Pascoe, John E. Corn, Jr., Dace Grote, \"Process for the production of isobutyric acid anhydride.\" U.S. Patent US4303594, issued September, 1936."@en . "2-Methyl-propionic acid"@en . . . . . . . . . . . . . . . . . . . . .