@incollection {shemyakova:winkler:hyperbolic:prop,
   author = {Shemyakova, Ekaterina and Winkler, Franz},
   affiliation = {J. Kepler University Research Institute for Symbolic Computation (RISC) Altenbergerstr. 69 A-4040 Linz Austria},
   title = {On the Invariant Properties of Hyperbolic Bivariate Third-Order Linear Partial Differential Operators},
   booktitle = {Computer Mathematics},
   series = {Lecture Notes in Computer Science},
   editor = {Kapur, Deepak},
   publisher = {Springer Berlin / Heidelberg},
   isbn = {},
   pages = {199-212},
   volume = {5081},
   url = {http://dx.doi.org/10.1007/978-3-540-87827-8_17},
   note = {10.1007/978-3-540-87827-8_17},
   year = {2008}
}