References
- Calbeck , W . 2008 . Elliptic numerical ranges of 3 × 3 companion matrices . Linear Algebra Appl. , 428 : 2715 – 2722 .
- Chen , YT . 2007 . Numerical ranges of companion matrices and normal operators , Master Thesis Taiwan : National Chiao Tung University . Available at http://etd.lib.nctu.edu.tw/cgi-bin/gs/tugsweb.cgi?o=dnctucdr&i=sGT009422520.id
- Gau , HL and Wu , PY . 1999 . Lucas' theorem refined . Linear Multilinear Alg. , 45 : 359 – 373 .
- Gustafson , KE and Rao , DKM . 1997 . Numerical Range: The Field of Values of Linear Operators and Matrices , New York : Springer .
- Horn , R and Johnson , CR . 2006 . Matrix Analysis , Cambridge : Cambridge University Press .
- Tan , C and Meng , Z . 2008 . Numerical ranges of 4 × 4 reducible companion matrices . Int. J. Algebra , 18 : 889 – 893 .
- Zemanek , J . 2003 . The derivative and linear algebra , 207 – 212 . Krakow : Kolo Mlodych Matematykow, Ogolnopolskie Warsztaty, dla Mlodych Matematykow .