Techniques of planing and upkeeped nursery young rubber in boeung ket rubber plantaion company,( បច្ចេកទេសដាំកៅស៊ូ និងការថែទាំ 426 នាក់ ថុន AGR នាក់ 1996 BOO17 Or.1 phnom phen RUA 1996 1996 Text 65P. eng