【作者(必填)】Margaret Armstrong, Romain Jabin

【文题(必填)】Variogram models must be positive-definite
【年份(必填)】Journal of the International Association for Mathematical Geology
October 1981, Volume 13, Issue 5, pp 455-459

【全文链接或数据库名称(选填)】http://link.springer.com/article/10.1007%2FBF01079648