1. 1972 Nonlinear Partial Differential Equations in Engineering, Vols. 1,2, Mathematics in Science and Engineering Vol. 18;Ames,1965
2. Conduction of Heat in Solids;Carslaw,1959
3. 1962 Methods of Mathematical Physics, Vols. 1,2;Courant,1953
4. Partial Differential Equations of Parabolic Type;Friedman,1964
5. Partial Differential Equations;Garabedian,1964