1. World Medical Association Declaration of Helsinki. Ethical principles for medical research involving human subjects. Adopted by the 18th World Medical Assembly, Helsinki, Finland, June 1964 and amended 2013. Available at http://www.wma.net/en/20activities/10ethics/10helsinki/. Accessed 7 January 2016.
2. Council for International Organizations of Medical Sciences (CIOMS). International Ethical Guidelines for Biomedical Research Involving Human Subjects. 2002, Geneva, Switzerland. Available at http://www.cioms.ch/publications/layout_guide2002.pdf. Accessed.
3. US Department of Health and Human Services. Code of Federal Regulations, 21 Part 50 Protection of Human Subjects and 45 part 46 Protection of Human Subjects, Federal Register 1991 June 18; 56: 28012. Available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=50. Accessed.
4. Beauchamp TL, Childress JF. Principles of biomedical ethics. 4th ed. New York: Oxford University Press; 1994.
5. Does informed consent to research require comprehension? Lancet;Sreenivasan G,2003