Khavandizadeh Aghdam,S , , Kazemzadeh,R , and Nikjoo,R . "The Effect of the Doula support During Labor on Delivery Length In Primigravida Women", The Iranian Journal of Obstetrics, Gynecology and Infertility, 18, 150, 2015, 8-13. doi: 10.22038/ijogi.2015.4574