K., S., and J. A. M. H. “Twin Pregnancy, the Study of Maternal and Perinatal Outcome: What Being a Twin Is Like?”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, vol. 8, no. 11, Oct. 2019, pp. 4457-61, doi:10.18203/2320-1770.ijrcog20194875.