@article{AM2_1994__48_2-3_137608,
     author = {Henrik Stetkaer},
     title = {D'Alembert's equation and spherical functions.},
     journal = {Aequationes mathematicae},
     pages = {220--227},
     publisher = {mathdoc},
     volume = {48},
     number = {2-3},
     year = {1994},
     zbl = {0810.39008},
     url = {http://geodesic.mathdoc.fr/item/AM2_1994__48_2-3_137608/}
}