Chemometric approach to validating faecal sterols as source tracer for faecal contamination in water. by Saim, Norashikin, Osman, Rozita, Abg Spian, Dayang Ratena Sari, Jaafar, Mohd Zuli, Juahir, Hafizan, Abdullah, Md Pauzi, Ab Ghani, Fuzziawati