1. Dewhurst’s textbook of obstetrics and gynecology, 9th edition, chapter 65.
2. Ali MM, Cleland JG, Shah IH, World Health Organization. Causes and consequences of contraceptive discontinuation: evidence from 60 demographic and health surveys. Geneva: World Health Organization; 2012.
3. Grimes DA, Gallo MF, Grigorieva V, et al. Fertility awareness-based methods for contraception. Cochrane Database Syst Rev. 2004;4:CD004860.
4. •• Fehring RJ, Schneider M, Barron ML, et al. Influence of motivation on the efficacy of natural family planning. MCN Am J Matern Child Nurs. 2013;38:352–8. This study highlights the importance of proper and mutual motivation and its effect on the efficacy of contraception in couples who used natural family planning methods such as fertility awareness-based methods which the use of mobile applications fall into.
5. •• Trussell J. Contraceptive efficacy. In: Hatcher R, Trussell J, Nelson AL, et al., editors. Contraceptive Technology (20th revised edn). New York: Ardent Media; 2011. p. 779–863. This study compares the effectiveness and measures of the risk of pregnancy between different contraceptive methods, while taking into account the typical and perfect use of each method. This study helped provide the figures of efficacy for the different methods of fertility awareness-based methods that can be used in concordance with the use of mobile applications in order to increase the efficacy of contraception.