1. Schmidt, Adolf, , , Tafeln der Normierten Kugelfunktionen, , Gotha, , 1935, ; see review in this number of Terr. Mag.
2. Sir Thomson, William, , , Reprint of Papers on Electrostatics and Magnetism, , §sect;494, London, , 1872, ; this remark is an addition, dated 1871, to the paper “A mathematical theory of magnetism,” Proc. R. Soc., London, 1849. For this reference and other remarks see the article by Ad. Schmidt in Encyclop. Math. Wiss., VI, 1, part 10.