This publication is cited in the following 2 articles:
Peter J. Bushell, World Congress of Nonlinear Analysts '92, 1996, 1523
Achim Clausing, International Series of Numerical Mathematics / Internationale Schriftenreihe zur Numerischen Mathematik / Série Internationale d'Analyse Numérique, 103, General Inequalities 6, 1992, 17