V. Fabian, Stochastic Approximation of Minima with Improved Asymptotic Speed, The Annals of Mathematical Statistics, vol.38, issue.1, pp.191-200, 1967.
DOI : 10.1214/aoms/1177699070

O. Shamir, On the complexity of bandit and derivative-free stochastic convex optimization, COLT 2013 -The 26th Annual Conference on Learning Theory, pp.3-24, 2013.