@InCollection{zbMATH01055053,
Author = {Rassias, John M.},
Title = {Solution of a stability problem of {Ulam}},
BookTitle = {Functional analysis, approximation theory and numerical analysis. Dedicated to Stefan Banach on his 100th birthday, Alexander Markowi\c{c} Ostrowski on his 99th birthday, Stanislaw Marcin Ulam on his 83rd birthday},
ISBN = {981-02-0737-9},
Pages = {241--249},
Year = {1994},
Publisher = {Singapore: World Scientific},
Language = {English},
Keywords = {46G05,41A65},
zbMATH = {1055053},
Zbl = {0878.46032}
}