Generalized symmetries of massless free fields on Minkowski space. Pohjanpelto, Juha, Anco, Stephen C. (2008) SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]
Group classification of the general evolution equation: local and quasilocal symmetries. Zhdanov, Renat, Lahno, Victor (2005) SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]
Group-theoretical solutions to gas dynamic equations generated by three-dimensional Lie subalgebras. Cherevko, A.A. (2007) Sibirskie Ehlektronnye Matematicheskie Izvestiya [electronic only]