smallholders rubber cultivation and maintenance techniques at memot district,បច្ចេកទេសដាំដុះនិងថែទាំចម្ការកៅស៊ូជាលក្ខណៈគ្រួសារ នៅស្រុកមេមត់ PHOEM KIMSAN,ភឹម គឹមសាន RUB PHO 2016 B614 Or.1 phnom penh RUA 2016 2016 Text ix;42p; https://drive.google.com/file/d/1sjh75FfFj3BN01xD1kunHnuP6xUxOeYN/view?usp=sharing