@article{SIGMA_2008_4_a84,
     author = {Petr Kulish and Vladimir Lyakhovsky},
     title = {String {Functions} for {Affine} {Lie} {Algebras} {Integrable} {Modules}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2008},
     volume = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2008_4_a84/}
}