Eventually rational and m-sparse points of linear ordinary differential operators with polynomial coefficients.

Sergei A. Abramov Eventually rational and m-sparse points of linear ordinary differential operators with polynomial coefficients. 3-13 2000 225 Discrete Mathematics 1-3 http://dx.doi.org/10.1016/S0012-365X(00)00144-8 db/journals/dm/dm225.html#Abramov00