4Briggs R E,et al.Attainting visual quality objectives in timber harvest areas landscape architects evaluation[D].USDA For Serv.Res Pap.INT-262.14P.1981.
5Danicl T C,Boster R S.Measuring landscape esthetics:The scenic beauty estimation method[D].USDA Forest Serv Res Pap RM-167,66p.Rocky Mtn Forest and Range Exp Stn.Fort Collins,Colo,1976.