Donald H. Hyers

Functions with Bounded nth Differences

George Isac, Themistocles M. Rassias, Donald H. Hyers, 1998 .

Approximately convex functions

S. M. Ulam, S. Ulam, D. H. Hyers, 1952 .

Approximate homomorphisms

Themistocles M. Rassias, T. Rassias, D. H. Hyers, 1992 .

On approximate isometries

Stanisław Ulam, S. Ulam, D. H. Hyers, 1945 .

Stability of Functional Equations in Several Variables

George Isac, Themistocles M. Rassias, G. Isac, 1998 .

Topics in Nonlinear Analysis and Applications

George Isac, Themistocles M. Rassias, G. Isac, 1997 .

Approximate Isometries of the Space of Continuous Functions

Stanisław Ulam, S. Ulam, D. H. Hyers, 1947 .