Günebak Şahin, Tuba, Berkan Sayal, Erdal Coşgun, Tanju Besler, and Sinan Beksaç. 2013. “Methylenetetrahydrofolate Reductase Enzyme Mutations and Relationship of Homocysteine Vitamin B12 and Folate Blood Levels”. Gynecology Obstetrics &Amp; Reproductive Medicine 19 (1). Ankara, TR:1-6. https://gorm.com.tr/index.php/GORM/article/view/171.