Metric characterizations of hyperbolic and Euclidean spaces J. E. Valentine; S. G. Wayment — 1972 Colloquium Mathematicae
A local metric characterization of Banach spaces J. E. Valentine; S. G. Wayment — 1981 Colloquium Mathematicae
Metric characterizations of Banach spaces J. E. Valentine; S. G. Wayment — 1973 Colloquium Mathematicae