@incollection {shemyakova:winkler:2007:invariants2,
   author = {Shemyakova, Ekaterina and Winkler, Franz},
   affiliation = {Research Institute for Symbolic Computation (RISC), J.Kepler University, Altenbergerstr. 69, A-4040 Linz Austria},
   title = {A Full System of Invariants for Third-Order Linear Partial Differential Operators in General Form},
   booktitle = {Computer Algebra in Scientific Computing},
   series = {Lecture Notes in Computer Science},
   editor = {Ganzha, Victor and Mayr, Ernst and Vorozhtsov, Evgenii},
   publisher = {Springer Berlin / Heidelberg},
   isbn = {},
   pages = {360-369},
   volume = {4770},
   url = {http://dx.doi.org/10.1007/978-3-540-75187-8_28},
   note = {10.1007/978-3-540-75187-8_28},
   year = {2007}
}