1. Evidence based medicine: what it is and what it isn’t;Sackett;BMJ,1996
2. Building an evidence house: challenges and solutions to research in complementary and alternative medicine;Jonas;Forsch Komplementarmed Klass Naturheilkd,2005
3. Part II: Framework and approach: II. 2 The evidence profile;Reilly;Complement Ther Med,1993
4. Medical study formats: an overview;van Haselen;J Biomed Ther,2010
5. Circular instead of hierarchical: methodological principles for the evaluation of complex interventions;Walach;BMC Med Res Methodol,2006