8[4]Ellis, Nair, Linehan, et al. A GIS-based Database Managcment Application for Agroforestry Planning and Tree Selection. Computcrs and Electronics in A griculture Volume, 2000, 27( 1-3): 41 - 55
9[5]Kambhampati S, Parker E, Lambrecht E. Undstanding and Extending Graphplan,In:Proc,4 th European Conferencc Panning, 1997
10[6]Carlos Z G, Enrique D I .Planning by Merging Totally Ordered Objcct Plans. Expert Systems with Applications, 1998,( 14): 71-81