Pongsuthirak, Pallop. 2019. “Comparison Between Headfirst and Tail-First Direction of Sperm for Intracytoplasmic Sperm Injection”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology 8 (11):4177-81. https://doi.org/10.18203/2320-1770.ijrcog20194601.