1. Steinitz field towers for modular fields;MacLane, Saunders;Trans. Amer. Math. Soc.,1939
2. Pure and Applied Mathematics, Vol. XIV;Abhyankar, Shreeram Shankar,1964
3. F. Aroca, Métodos algebraicos en ecuaciones diferenciales ordinarias en el campo complejo, Tesis Doctoral, Universidad de Valladolid, 2000.
4. Formal solutions of linear PDEs and convex polyhedra;Aroca, F.;J. Symbolic Comput.,2001
5. Memorias de Matem\'{a}tica del Instituto ``Jorge Juan'' [Mathematical Memoirs of the Jorge Juan Institute];Aroca, José M.,1977