Ekaterina Shemyakova, Franz Winkler. On the Invariant Properties of Hyperbolic Bivariate Third-Order Linear Partial Differential Operators. In Deepak Kapur, editor, Computer Mathematics, 8th Asian Symposium, ASCM 2007, Singapore, December 15-17, 2007. Revised and Invited Papers. Volume 5081 of Lecture Notes in Computer Science, pages 199-212, Springer, 2007. [doi]
Abstract is missing.