Boulton M, Fitzpatrick R. Qualitative methods for assessing health care. Quality in Health Care 1994; 3: 107-113.
Britten N, Jones R, Murphy E, Stacey R. Qualitative research methods in general practice and primary care. Family Practice 1995; 12:104-114
Esterberg KG. Qualitative Methods in Social Research. Boston (US): McGraw-Hill, 2002.
Giacomini MK. The rocky road: qualitative research as evidence. Evidence-Based Medicine 2001; 6: 4-5
Grbich C. Qualitative Research in Health: An Introduction. London (UK): Sage Publications, 1999.
Green J, Britten N. Qualitative research and evidence-based medicine. BMJ 1998; 316:1230-2.
Guba RG, Lincoln YS. Competing paradigms in qualitative research. In: Denzin NK, Lincoln YS (Eds) Handbook of Qualitative Research. Thousand Oaks (CA): Sage Publications, 1994.
Miller S, Fredericks M. The nature of “evidence” in qualitative research methods. International Journal of Qualitative Methods 2003; 2: Article 4. Retrieved 1 January 2008 from http://www.ualberta.ca/~ijqm.
Murphy E, Dingwall R, Greatbach D, Parker S, Watson P. Qualitative research methods in health technology assessment: a review of the literature. Health Technology Assessment 1998; 2: 1–274.
Popay J, Williams G. Qualitative research and evidence based healthcare. Journal of the Royal Society of Medicine 1998; 91(Suppl 35):32–37.
Pope C, Mays N. Qualitative research: reaching the parts other methods cannot reach: an introduction to qualitative methods in health and health service research. BMJ 1995; 311: 42-45.
Pope C, Van Royen P, Baker R. Qualitative methods in research on healthcare quality. Quality and Safety in Health Care 2002; 11:148-152.