1. Approaches to Social Research;Singleton,2010
2. Survey Methodology;Groves,2009
3. Designing and Conducting Health Surveys: A Comprehensive Guide;Aday,2006
4. Patient-Centered Outcomes Reseach Institute. https://www.pcori.org/. Accessed 8 July 2018.
5. Hernia survey of the Section on Surgery of the American Academy of Pediatrics;Wiener;J Pediatr Surg,1996