n inequality due to T. J. Rivlin from 1960 states that if $P(z)$ is a polynomial of degree $n$ having no zeros in $ z
KUMAR, PRASANNA and MILOVANOVIC, GRADIMIR
"On sharpening and generalization of Rivlin's inequality,"
Turkish Journal of Mathematics: Vol. 46:
4, Article 24.
Available at: https://journals.tubitak.gov.tr/math/vol46/iss4/24