Proceedings of the Soil Science Conference of Malaysia 2007: Peat and Other Soil Factors in Crop Production: Sarawak (Malaysia), 17-19 Apr 2007, p. 202-208
Proceedings 4th Malaysian International Cocoa Conference: Sustainable Cocoa Economy Through Increase in Productivity, Efficiency and Quality: Kuala Lumpur (Malaysia), 18-19 Jul 2005, p. 142-146
Proceedings of the Malaysian Society of Soil Science Conference 2002 : Applications of Modern Tools in Agriculture: Perlis (Malaysia), 23-24 Apr 2002, p. 208-211