1C. Canuto,S. I. Hariharan,L. Lustman. Spectral methods for exterior elliptic problems[J] 1985,Numerische Mathematik(4):505~520
2E. L. Ortiz,H. Samara. Numerical solution of differential eigenvalue problems with an operational approach to the Tau method[J] 1983,Computing(2):95~103
3Ivo Babu?ka,Milo R. Dorr. Error estimates for the combinedh andp versions of the finite element method[J] 1981,Numerische Mathematik(2):257~277