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. 234-236
Proceedings of the Malaysian Society of Soil Science Conference 2002 : Applications of Modern Tools in Agriculture: Perlis (Malaysia), 23-24 Apr 2002, p. 15-19
Proceedings of the Soil Science Conference of Malaysia 2007: Peat and Other Soil Factors in Crop Production: Sarawak (Malaysia), 17-19 Apr 2007, p. 233-247