@article{2001, author = {Protter, M.H.}, title = {On a class of harmonic polynomials}, journal = {Portugaliae mathematica}, volume = {10}, year = {1951}, pages = {11-22}, zbl = {0043.07302}, mrnumber = {0041993}, language = {en}, url = {http://dml.mathdoc.fr/item/2001} }
Protter, M.H. On a class of harmonic polynomials. Portugaliae mathematica, Tome 10 (1951) pp. 11-22. http://gdmltest.u-ga.fr/item/2001/