ELA articles which reference this paper are

Vladimir Bolotnikov; Chi-Kwong Li; Patrick R. Meade; Christian Mehl; Leiba Rodman
Shells of matrices in indefinite inner product spaces,
Electron. J. Linear Algebra 9 (2002), 67-92.

Natalia bebiano; Joao da Providencia; Ana Cristina Nata; Maria da Graca Pereira Soares
Krein spaces numerical ranges and their computer generation,
Electron. J. Linear Algebra 17 (2008), 192-208.