@article{02186439, title = {Constructing homomorphisms between Verma modules.}, journal = {Journal of Lie Theory}, volume = {15}, year = {2005}, pages = {415-428}, zbl = {1064.17004}, language = {en}, url = {http://dml.mathdoc.fr/item/02186439} }
de Graaf, Willem A. Constructing homomorphisms between Verma modules.. Journal of Lie Theory, Tome 15 (2005) pp. 415-428. http://gdmltest.u-ga.fr/item/02186439/