【作者(必填)】Paul Krugman

【文题(必填)】On the number and location of cities

【年份(必填)】European Economic Review Volume 37, Issues 2–3, April 1993, Pages 293–298

【全文链接或数据库名称(选填)】http://www.sciencedirect.com/science/article/pii/0014292193900175