Douglas S. Bridges, Robin Havea. Approximations to the numerical range of an element of a Banach algebra. In Laura Crosilla, Peter M. Schuster, editors, From sets and types to topology and analysis - Towards practicable foundations for constructive mathematics. Volume 48 of Oxford logic guides, Oxford University Press, 2005.
@incollection{BridgesH05,
title = {Approximations to the numerical range of an element of a Banach algebra},
author = {Douglas S. Bridges and Robin Havea},
year = {2005},
researchr = {https://researchr.org/publication/BridgesH05},
cites = {0},
citedby = {0},
booktitle = {From sets and types to topology and analysis - Towards practicable foundations for constructive mathematics},
editor = {Laura Crosilla and Peter M. Schuster},
volume = {48},
series = {Oxford logic guides},
publisher = {Oxford University Press},
isbn = {978-0-19-856651-9},
}