%0 Journal Article %A Aleksander Strasburger %T Differential operators of gradient type associated with spherical harmonics %J Annales Polonici Mathematici %D 1991 %P 161-183 %V 53 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/ap-53-2-161-183/ %R 10.4064/ap-53-2-161-183 %G en %F 10_4064_ap_53_2_161_183