Proceedings of the Seminar on Medicinal and Aromatic Plants: Towards Modernisation of Research and Technology in Herbal Industries: Kuala Lumpur (Malaysia), 24-25 Jul 2002, p. 246-253
Proceedings of the Malaysian Society of Soil Science Conference 2002 : Applications of Modern Tools in Agriculture: Perlis (Malaysia), 23-24 Apr 2002, p. 60-61
Proceedings of the Soils Science Conference of Malaysia 2008: Sustaining Soil Ecosystems with Emphasis on Coastal Soils: Perak (Malaysia), 15-17 Apr 2008, p. 4-8