References
- Gau , H.-L. and Wu , P. Y. Numerical range of S(φ) . Linear and Multilinear Algebra , 45 49 – 73 .
- Gau , H.-L. and Wu , P. Y. Dilation to inflations of S(φ) . Linear and Multilinear Algebra , 45 109 – 123 .
- Gau , H.-L. and Wu , P. Y. Uniqueness of elliptical numerical range , 45 preprint
- Marden , M. 1966 . Geometry of Polynomials . Amer. Math. Soc , 45 Providence
- Siebeck , J. 1864 . Über eine neue analytische behandlung weise der brennpunkte . J. Reine Angew. Math , 64 : 175 – 175 .