Valkova, Lyuboslava, Tanya Milachich, Tanya Timeva, and Atanas Shterev. “Combined Artificial Collapse and Assisted Hatching Increase the Success Rate in Frozen Embryo Transfer”. Proceedings of the Bulgarian Academy of Sciences 75, no. 6 (June 30, 2022): 901–907. Accessed March 23, 2023. https://proceedings.bas.bg/index.php/cr/article/view/105.