L. N. Muhati, J. O. Bonyo, J. O. Agure
      Some properties of the essential numerical range on Banach spaces
      Pure Mathematical Sciences, Vol. 6, 2017, no. 1, 105-111
      https://doi.org/10.12988/pms.2017.7912

Copyright © 2017 L. N. Muhati, J. O. Bonyo and J. O. Agure. This article is distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.