1. Servqual revisited: A critical review of service quality;Asubonteng;Journal of Services Marketing,1996
2. Product service systems, ecological and economic basics;Goedkop;Journal of Services Marketing,1999
3. Clarifying the concept of product– service system;Mont;Journal of Clean Prod.,2002
4. W. R. Stahel. 1997. The functional economy: cultural change and organizational change. Ind. Green Game. 91–100. 2002.
5. Eight types of product-service system: Eight ways to sustainability, experiences from SusProNet;Parasuraman;Business Strategy and the Environment,2004