3Cuperus R,Caters K J,Piepers A A G. Ecological compensation of the impacts of a wad:Preliminary method of A50 road link [J]. Ecological Engineering, 1996(7) : 327- 349.
4Allen A O, Feddema J J. Wetland Loss and Substitution by the Permit Program in Southern Califomia[J].US Environmental Management, 1996, 20(22) : 263- 274.