The following publications should be helpful, namely: history of qualitative research/qualitative research as scientific theory building (see: Alasuutari, 2010, pp. 141-147); characteristics of Qualitative Content Analysis (see: White and Marsh, 2006, pp. 35-36), etc.
Alasuutari, P. (2010) The rise and relevance of qualitative research, International journal of social research methodology, 13, 2, pp. 139-155.
Bengtsson, M. (2016) How to plan and perform a qualitative study using content analysis, Nursing Plus Open, 2, s, pp. 8-14.
Black, N. (1994) Editorial: Why we need qualitative research, Journal of epidemiology and community health, 48, 5, pp. 425-426.
Blank, G. (2004) Teaching qualitative data analysis to graduate students, Social Science Computer Review, 22, 2, pp. 187-196.
Bryman, A. and Burgess, R. G. (2002) Analyzing qualitative data. London: Routledge.
Creswell, J. W. (2009) Research Design: Qualitative, Quantitative, and Mixed Methods Approaches. Third edn. London: SAGE Publications Inc.
Hsieh, H.-F. and Shannon, S. E. (2005) Three Approaches to Qualitative Content Analysis, Qualitative Health Research, 15, 9, pp. 1277-1288.
Keen, M. F. (1996) Teaching Qualitative Methods: A Face-to-Face Encounter, Teaching Sociology, 24, 2, pp. 166-176.
Krippendorf, K. (2004) Content Analysis: An Introduction to its Methodology. 2nd edn. London: Sage Publications, Inc.
Poulin, K. L. (2007) Teaching Qualitative Research: Lessons From Practice, The Counseling Psychologist, 35, 3, pp. 431-458.
Silverman, D. and Marvasti, A. (2008) Doing Qualitative Research: A Comprehensive Guide. California: SAGE Publications, Inc.
Turner III, D. W. (2010) Qualitative interview design: A practical guide for novice investigators, The qualitative report, 15, 3, pp. 754-760.
White, M. D. and Marsh, E. E. (2006) Content analysis: A flexible methodology, Library trends, 55, 1, pp. 22-45.
Further to my post as aforesaid, please refer to the following papers for an illustration of the strengths/weaknesses of qualitative research (see: Libarkin and Kurdziel, 2002, pp. 78-79; Johnson and Onwuegbuzie, 2004, pp. 19-20; Schulze, 2003, p. 12).
Johnson, R. B. and Onwuegbuzie, A. J. (2004). Mixed Methods Research: A Research Paradigm Whose Time Has Come. Educational Researcher, 33, 7, pp. 14-26.
Libarkin, J. C. and Kurdziel, J. P. (2002). Research Methodologies in Science Education: The Qualitative-Quantitative Debate. Journal of Geoscience Education, 50, 1, pp. 78-79.
Schulze, S. (2003). Views on the combination of quantitative and qualitative research approaches. Progressio, 25, 2, pp. 8-20.