Chi-Kwong Li, Leiba Rodman. Numerical Range of Matrix Polynomials. SIAM J. Matrix Analysis Applications, 15(4):1256-1265, October 1994. [doi]
@article{LiR94-1,
title = {Numerical Range of Matrix Polynomials},
author = {Chi-Kwong Li and Leiba Rodman},
year = {1994},
month = {October},
doi = {10.1137/s0895479893249630},
url = {https://doi.org/10.1137/s0895479893249630},
researchr = {https://researchr.org/publication/LiR94-1},
cites = {0},
citedby = {0},
journal = {SIAM J. Matrix Analysis Applications},
volume = {15},
number = {4},
pages = {1256-1265},
}