Shihata Alfred, et al. “Study on Multipurpose, Reusable, Female Contraceptive Device for Enhancing the Effectiveness of Fertility Awareness Methods and Controls Stress Incontinence”. New Frontiers in Medicine and Medical Research Vol. 6, Aug. 2021, pp. 81-89, doi:10.9734/bpi/nfmmr/v6/1836C.