1. The Marketing of Professional Services;Wilson,1972
2. How to Sell/Buy Professional Services;Wittreich;Harvard Business Review,1966
3. Marketing Professional Services;Kotler;Journal of Marketing,1977
4. Toward a Theory of Professional Services;Gummesson;Industrial Marketing Management,1978
5. The Marketing of Professional Services—An Organizational Dilemma;Gummesson,1978