Beltran, JarnishsReyes, Enrique G.2016-01-282016-01-282015Advances in Mathematical Physics, 2015, 16 p.http://hdl.handle.net/11447/214http://dx.doi.org/10.1155/2015/210346en-USAlgebraFormal Pseudodifferential Operators in One and Several Variables, Central Extensions, and Integrable SystemsArtÃculo