求助格式： 【篇号】Radiation pattern of surface waves from point sources in a multi-layered medium 【作者】N. A. Haskell 【文章标题】Radiation pattern of surface waves from point sources in a multi-layered medium 【期刊名，年份，卷（期），起止页*****】Bulletin of the Seiological Society of America February1964 54:377-393 【全文链接】 http://www.bssaonline.org/content/54/1/377.refs