【作者(必填)】Johannes Järemo,

【文题(必填)】Evaluating spread of invaders from gravity scores – A way of using gravity models in ecology

【年份(必填)】mathematical Biosciences，Volume 222, Issue 1, November 2009, Pages 53-58
【全文链接或数据库名称(选填)】http://www.sciencedirect.com/science/article/pii/S0025556409001461

thanks。