1. Breech presentation and perinatal mortality;Hall;Am J Obstet Gynecol,1965
2. Analysis of 16,327 breech births;Morgan;JAMA,1964
3. Abdominal versus vaginal delivery in breech presentation A retrospective study comparing 420 breech presentations for infants weighing more than 2500 g at birth;Fischer-Rasmussen;Acta Obstet Gynecol Scand,1967
4. Breech presentation at term;Johnson;Am J Obstet Gynecol,1970