Volume 15, Issue 1 Choonkil Park Derivation-homomorphism functional inequalities Downloads Abstract PDF Full article PDF DOI { copied = true; setTimeout(() => copied = false, 2000) })" :aria-label="copied ? 'DOI copied' : 'Copy DOI'" :title="copied ? 'Copied' : 'Copy DOI'" > Find all available articles from these authors Choonkil Park Find more articles with the same keywords Hyers-Ulam stability direct method fixed point method additive-additive (s,t)-functional inequality derivation in Banach algebra homomorphism in Banach algebra Find more articles with the same subject classes 47B47 17B40 39B72 39B62 39B52