M. A. Alsammani, M. A. Alsheeha, S. R. Ahmed, and A. M. Abdalla, “The effect of advanced maternal age on pregnancy outcome in women with cervical insufficiency treated with cerclage: The effect of advanced maternal age on pregnancy outcome”, Natl J Integr Res Med, vol. 3, no. 3, pp. 63–67, Aug. 2012.