1. Faculty of Natural Resources and Environment Vietnam National Univ. of Agriculture Ngo Xuan Quang St. Trau Quy District Ha Noi Viet Nam
2. Dep. of Science and Technology Hong Ha St. Ha Long City Quang Ninh Province Viet Nam
3. Soils and Fertilizers Research Institute No 10 Le Van Hien St., Dong Ngac commune Tu Liem Ha Noi Viet Nam
4. Hawkesbury Institute for the Environment Western Sydney Univ. LB1797 Penrith NSW 2751 Australia