fatma omran m. alahmr, murnira othman, nurul bahiyah abd wahid, azhar abdul halim, mohd talib latif.  (2012).  compositions of dust fall around semi-urban areas in malaysia.  - aerosol and air quality research.  12(4):629-642. 

azhar abdul halim, hamidi abdul aziz, megat azmi megat johari, kamar shah ariffin, mohd. nordin adlan.  (2010).  ammoniacal nitrogen and cod removal from semi-aerobic landfill leachate using a composite adsorbent : fixed bed column adsorption performance.  - journal of hazardous materials.  175(1-3):960-964. 

azhar abdul halim, hamidi abdul aziz, megat azmi megat johari, kamar shah ariffin.  (2010).  comparison study of ammonia and cod adsorption on zeolite, activated carbon and composite materials in landfill leachate treatment.  - desalination.  article in press.