The assessment of the variation of physico-chemical sources for drinking water quality using chemometrics: A case study at water treatment plants in Klang Valley по Rwoo, M.A., Juahir, H., Roslan, N.M., Toriman, M.E., Endut, A., Azid, A., Che Hasnam, C.N., Mohd Saudi, A.S., Kamarudin, M.K.A., Rwoo, S.A., Mustafa, A.D.