@article{PORMA_1966__25_3_114981, author = {Biesterfeldt, H.J. jr.}, title = {Expansions of solutions to a hypoelliptic differential equation in terms of polynomiallike solutions}, journal = {Portugaliae mathematica}, pages = {123--128}, publisher = {mathdoc}, volume = {25}, number = {3}, year = {1966}, mrnumber = {0233990}, zbl = {0173.12103}, language = {en}, url = {http://geodesic.mathdoc.fr/item/PORMA_1966__25_3_114981/} }