1. Meromorphic Function;Hayman,1964
2. Value Distribution Theory and New Research;Yang,1982
3. The Uniqueness Theory of Meromorphic Functions;Yi,1995
4. Ordinary Differential Equations in the Complex Domain;Hille,1976
5. Uber die subnormalen losungen der differentialgleichung w″ + e–z w′ + (konst.)w = 0;Frei;Comment Math Helv,1962