Susan Zwyea, K. S. S. S. K. A. A. A. “A Comparative Study Between Transabdominal and Transvaginal Ultrasound Techniques in Early Detection of Ectopic Pregnancy”. Annals of the Romanian Society for Cell Biology, May 2021, pp. 16128-36, http://annalsofrscb.ro/index.php/journal/article/view/5354.