9BECK M. The identification and adaptive prediction of urban sewer flows[ G]. Optimization techniques modeling and optimization in the service of man:Part 1,1976:246 -263.
10CARROLL S, GOONETILLEKE A. Assessment of high density of onsite wastewater treatment systems on a shallow groundwater coastal aquifer using PCA [ J ]. Environmetrics ,2005,16 (3) :257 - 274.