1. Reply.;Nesheim;Acta Obstet Gynecol Scand
2. Fetal sex and severe hyperemesis gravidarum.;Hsu;Int J Gynaecol Obstet,1993
3. First trimester nausea and vomiting as related to outcome of pregnancy.;Brandes;Obstet Gynecol,1967
4. Impact of sex ratio on onset and management of labour.;Pickard;Br Med J,1982