Effectiveness of cerclage according to severity of cervical length shortening: a meta-analysis.Published in:Ultrasound in Obstetrics & Gynecology, 2010, v. 35, n. 4, p. 468, doi. 10.1002/uog.7547By:Berghella, V.;Keeler, S. M.;To, M. S.;Althuisius, S. M.;Rust, O. A.Publication type:Article