Volume 24, Issue 3 Feng Qi Necessary and sufficient conditions for a difference constituted by four derivatives of a function involving trigamma function to be completely monotonic 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 Feng Qi Find more articles with the same keywords complete monotonicity necessary and sufficient condition difference derivative trigamma function convolution theorem for the Laplace transforms Bernstein's theorem for completely monotonic functions Find more articles with the same subject classes 33B15 26A48 26A51 26D07 44A10