1. Clinical practice guidelines we can trust [Internet],2011
2. Evidence based medicine: what it is and what it isn’t;Sackett;BMJ,1996
3. Bowel Preparation for Colorectal Procedures: A Review of Clinical Effectiveness, Cost-Effectiveness and Guidelines [Internet];la Fleur,2018
4. Committee on Standards for Developing Trustworthy Clinical Practice Guidelines; Institute of Medicine. Clinical Practice Guidelines We Can Trust,2011
5. GRADE guidelines 3: rating the quality of evidence;Balshem;J Clin Epidemiol.,2011