1. Srivastava S.K./Kailash Chandra Barmola (2011) Role of Motivation in higher Productivity.Management Insight, Vol. VII, No. 1; June, 2011.
2. European Commission (2007): Towards a European strategy in support of innovation in services, Brussels:.
3. Furnham A./Eracleous A. (2009): Personality, motivation and job satisfaction: In Journal of Managerial Psychology, 24, p.765-779.
4. Lynn, Susan A. (1986): Segmenting a Business Market for a Professional Service. In Industrial Marketing Management, 15, p.13-21.
5. Meier H/Lagemann H (2013): KPI for Assessing the Planning and delivery of Industrial Services Ruhr-Universität Bochum.