1.M iller， P． et a1． 200i“Business Clusters in the UK ， First Assessment，”Department of Trade and Industry，
       U niversity of Cam bridge，W orking Poper 1 3 2．
  2 Keeble．D ， L． Nachum． 2001． W hy Do Business Service Firms Cluster? Small Consultancies Clustering and
     Decentralization in London and Southern England，” ESRC Centre for Business Research，University of Cambridge，
     W orking Paper 1 94．

有相关的服务业的英文文献就可以。谢谢！