An iff fixed point criterion for continuous self-mappings on a complete metric space. (Summary). J. Jachymski — 1994 Aequationes mathematicae
An iff fixed point criterion for continuous self-mappings on a complete metric space. J. Jachymski — 1994 Aequationes mathematicae
Projections, extendability of operators and the Gâteaux derivative of the norm. Gajek, L.; Jachymski, J.; Zagrodny, D. — 1995 Journal of Applied Analysis