<p>1</p>文献名：The location of sales offices and the attraction of cities <p></p>作者：Thomas J. Holmes <p></p>期刊：Journal of Political Economy, 2005, vol. 113, issue 3, pages 551-581 <p></p><p>电子链接：<a href="http://www.journals.uchicago.edu/toc/jpe/2005/113/3">http://www.journals.uchicago.edu/toc/jpe/2005/113/3</a></p><p></p><p>2</p>文献名：Information, agglomeration, and the headquarters of U.S. exporters <p></p>作者：Mary E. Lovely, Stuart S. Rosenthal and Shalini Sharma <p></p>期刊：Regional Science and Urban Economics, 2005, vol. 35, issue 2, pages 167-191 <p></p><p>电子链接：<a href="http://www.sciencedirect.com/science/article/B6V89-4BY3SYW-1/2/7ab11a16c633cb3d6e429b2cf47365e4">http://www.sciencedirect.com/science/article/B6V89-4BY3SYW-1/2/7ab11a16c633cb3d6e429b2cf47365e4</a></p><p></p><p>3</p>文献名：Product variety, marshallian externalities, and city sizes <p></p>作者：Hesham Abdel-Rahman 1 Masahisa Fujita <p></p><p>期刊：Journal of Regional Science,2006,Volume 30 Issue 2,&nbsp;Pages&nbsp;165&nbsp;-&nbsp;183</p><p>电子链接：<a href="http://www3.interscience.wiley.com/journal/119997502/abstract?CRETRY=1&amp;SRETRY=0">http://www3.interscience.wiley.com/journal/119997502/abstract?CRETRY=1&amp;SRETRY=0</a></p><p></p>