1   相关链接： http://www.energystorm.us/Shortest_Path_Ray_Tracing_With_Sparse_Graphs-r107815.html
           或者 http://adsabs.harvard.edu/abs/1993Geop...58..987F
    作者：Fischer R and Lees J M.
    题目：Shortest path ray tracing with sparse graphs.
    期刊：Geophysics,
    卷期年页：1993, 58(7): 987~996

2  相关链接： http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.1993.tb06989.x/abstract
    作者：Cao S　, Greenhalgh S.
    标题：Calculation of the seismic first-break time field and its ray path distribution using a minimum traveltime tree algorithm.
    期刊：Geohys. J. Int,
    年卷期页：1993, 114(3): 593~600