1. Phillips B, Ball C, Sackett D, et al. Oxford Centre for Evidence-based Medicine levels of evidence. Updated by Jeremy Howick; March 2009. https://www.cebm.net/2009/06/oxford-centre-evidence-based-medicine-levels-evidence-march-2009/ [accessed April 24, 2020].
2. What is "quality of evidence" and why is it important to clinicians?;Guyatt;BMJ,2008
3. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations;Guyatt;BMJ,2008
4. EAU-ESMO consensus statements on the management of advanced and variant bladder cancer-an international collaborative multi-stakeholder effort: under the auspices of the EAU and ESMO Guidelines Committees;Witjes;Eur Urol,2020
5. EAU-ESMO consensus statements on the management of advanced and variant bladder cancer-an international collaborative multi-stakeholder effort: under the auspices of the EAU and ESMO Guidelines Committees;Horwich;Ann Oncol,2020