Volume 10, Issue 1 Ling Zhu A solution of a problem of Oppeheim 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 Ling Zhu Find more articles with the same keywords Oppenheim's problem Shafer inequality Fink inequality Malesevic inequality Find more articles with the same subject classes 26D15