Oranratnachai, Apichart, Teraporn Vutyavanich, Chamnong Uttavichai, Prayode Jongyusuk, Pallop Pongsuthirak, Warunya Ittipunkul, and Waraporn Piromlertamorn. 1991. “Two-year Experience with Gamete Intrafallopian Trans fer (GIFT) at Maharaj Nakorn Chiang Mai Hospital”. Thai Journal of Obstetrics and Gynaecology 3 (2). Bangkok, Thailand:95-102. https://he02.tci-thaijo.org/index.php/tjog/article/view/257864.