A.W.Adamson, Physical Chemistry of Surfaces, 3rd Edn.,Wiley Interscience, 1976. A. Clark, The Theory of Adsorption and Catalysis Academic Press, 1970. D.K.Chakrabarty, Adsorption and catalysis by solids, Wiley Eastern, 1990. F.P.Kane and G.B.Larrabee (Eds.),Characterisation of solid surfaces, Plenum, N.Y.,1978.