@article{SIGMA_2014_10_a7,
     author = {Toshihisa Kubo},
     title = {Systems of {Differential} {Operators} and {Generalized} {Verma} {Modules}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2014},
     volume = {10},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2014_10_a7/}
}