A. Tukker, Eight types of product???service system: eight ways to sustainability? Experiences from SusProNet, Business Strategy and the Environment, vol.13, issue.4, pp.246-260, 2004.
DOI : 10.1002/bse.414

I. M. Walton and H. Wilson, State-of-the-art in product-service systems, Proceedings of the Institution of Mechanical Engineers Nr. 10, pp.1543-1552, 2007.

M. Goedkoop, C. Van-halen, H. Te-riele, and P. Rommens, Product service systems, ecological and economic basics. The Hague: Ministry of Housing, Spatial Planning and the Environment Directorate, Communications, 1999.

M. Abramovici and S. Schulte, Lifecycle Management für hybride Leistungsbündel (HLB) In: wt Werkstattstechnik online, pp.467-471, 2006.

D. Spath and L. Demuß, Entwicklung hybrider Produkte ? Gestaltung materieller und immaterieller Leistungsbündel, Hrsg.): Service Engineering: Entwicklung und Gestaltung innovativer Dienstleistungen. 2., vollständig überarbeitete und erweiterte Auflage, pp.463-502, 2006.

E. Von-hippel, The Sources of Innovation, 1988.
DOI : 10.1007/978-3-8349-9320-5_10

A. K. Chatterji and K. Fabrizio, How Do Product Users Influence Corporate Invention?, Organization Science, vol.23, issue.4, pp.971-987, 2012.
DOI : 10.1287/orsc.1110.0675

D. M. Schmidt, S. Preissner, J. A. Hermosillo-martinez, M. Quiter, M. Mörtl et al., Integration of user knowledge across the lifecycle of integrated product-service systems ? An empirical analysis of the relevance for PSS development and management, ICED ? International Conference of Engineering Design, 2015.

R. K. Yin, Case study research: Design and methods (2013)

U. Flick, An introduction to qualitative research, 2009.

M. B. Miles, A. M. Huberman, and J. Saldana, Qualitative Data Analysis: A Methods Sourcebook, 2013.