1. Winning in the Aftermarket;Cohen;Harvard Business Review,2006
2. Crespo, A. (2007). The Maintenance Management Framework: Models and Methods for Complex Systems Maintenance.
3. Marshall Institute (1999) Maintenance Effectiveness Survey. Retrieved February 2, 2016, from http://www.marshallinstitute.com/inc/eng/consulting/areas/customized_reliability_solutions/body/measurvey.pdf.
4. Qualitative Research & Evaluation Methods;Patton,2001
5. The Balanced Scored – measures that drive performance;Kaplan;Harvard Business Review,1992