1. �ber die partiellen Differenzengleichungen der mathematischen Physik
2. The Calculus of Finite Differences;Milne-Thomson,1951
3. Tables of the Complete and Incomplete Elliptic Integrals;Legendre,1934
4. “Methods of Theoretical Physics,” Part II;Morse,1953
5. Finite Differences and Difference Equations in the Real Domain;Fort,1948