RETRACTED: Anastrozole or letrozole for ovulation induction in clomiphene-resistant women with polycystic ovarian syndrome: a prospective randomized trial.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the ASRM Publications Committee. Several reports of randomized clinical trials were recently the subject of an investigation conducted by the publications committee of the ASRM. The committee reviewed concerns related to the validity of data reported in those reports. The committee noted significant duplication of data reported in this manuscript with data reported in another report (PMID: 19732888; https://doi.org/10.1016/j.fertnstert.2009.07.985) pertaining to a different study group that could not be explained. As we cannot vouch for the validity of the data, we have issued a retraction of this paper.