Spectroscopic and chromatographic techniques for the forensic discrimination of laser-jet printer toners / by Umi Kalthom Ahmad, author, Widyaratih Hafizah Mechor, 1987-, author, Asian Conference on Analytical Science (10th : 2009 : Kuala Lumpur)

Enhancement of natural organic removal from raw water and treated water using Zeolite / by Umi Kalthom Ahmad, author, Roslan Omar, author, Widyaratih Hafizah Mechor, 1987-, author, Environmental Science and Technology Conference (ESTEC2009) (2009 : Terengganu)