1. Anderson, E. W., Fornell, C., and Rust, R. T. (1997). Customer satisfaction, productivity, and profitability: Differences between goods and services. Marketing Science, 16(2), 129–145.
2. Bessant, J., and Davies, A. (2007). Managing Service Innovation, Innovation in Services, DTI Occasional Paper no 9: 61–96: UK Department of Trade and Industry.
3. BIMCO/ISF. (2005). Manpower 2005 update. Coventry, UK: Warwick Institute for Employment Research.
4. de Blok, C., Luijkx, K., Meijboom, B., and Schols, J. (2010). Modular care and service packages for independently living elderly. International Journal of Operations and Production Management, 30(1), 75–97
5. Done, A., Schmeer, F., and Voss, C. A. (2001). The Woolwich Bank, Project Lifestyle. Cranfield: European Case Clearing House