【作者(必填)】Krugman

【文题(必填)】First Nature, Second Nature, and Metropolitan Location

【年份(必填)】Journal of Regional Science Volume 33, Issue 2, pages 129–144, May 1993

【全文链接或数据库名称(选填)】http://onlinelibrary.wiley.com/doi/10.1111/j.1467-9787.1993.tb00217.x/abstract