Bowater RJ, Hartley LC, Lilford RJ. Are cardiovascular trial results systematically different between North America and Europe? A study based on intra-meta-analysis comparisons. Arch Cardiovasc Dis. 2015 Jan;108(1):23-38. doi: 10.1016/j.acvd.2014.03.005
Johannes CB, Caro JJ, Hartz SC, Marrs R. Adverse effects of ovulatory stimulants: a review. Assist Reprod Rev. 1993;3:68-74.