Oscillation Theorems in the Complex Domain
Einar Hille · Transactions of the American Mathematical Society · 1922
problems concerning spherical harmonics, Arkiv for Matematik, Astrono m i och Fysik, vol.13 (1918), No. 17. * On the zeros of Legendre functions, Arkiv for Matematik, Astronomi och Fysik, vol.17 (1922), No. 22. * This function has of course nothing to do with the classical r-function.* Cf. for the theory of curves of this kind F. Lucas, Géométrie des polynômes, Journal de