3Andrew Sharpe (2000):The productivity renaissance in the U.S. service Sector, International Productivity Monitor, No. 1 (Fall, 2000)
4David Keeble and Lilach Nachum(2001):Why do business seervice firms cluster? small consultancies ,clustering and decentralization in London and Southern England, University of Cambridge Working Paper No. 194
5David P. Lindahl and William B. Beyers(1999):The creation competitive advantage by producer services establishments,Economic Geography, Vol. 75, No. 1
6Eric C. Thompson(2004) : Producer Services, Kentucky Annual Economic Report
7Joseph F. Francois (1990) : producer services, scale and the division of labor, Oxford Economic Papers,New Series, Vol. 42, No. 4 (Oct.,1990),715-729
8John Tschetter (1987): Producer services industries: Why are they growing so rapidly? Monthly Labor Review. (December)
9John R. Bryson,David Keeble and Peter Wood(1997) : The Creation and Growth of Small Business Service Firms in Post-Industrial Britain. Small Business Economics 9:345-360
10Laszlo Drechsler(1990) :A note on the concept of services, Review of income and wealth, series36, Number 3
