Salari, P., Alavian, F., Habibi Rad, A., & Tara, F. "The Relationship between Stress, Anxiety and Pain with Salivary Cortisol Levels in First Stage of Labor in Primiparous Women", The Iranian Journal of Obstetrics, Gynecology and Infertility, 16, 55, 2013, 14-21. doi: 10.22038/ijogi.2013.1174