6Pandey S, Velasco L. Economics of direct seeding in Asia:patterns of adoption and research priorities [A]. // Pandey S, Mortimer M, Wade L, et al. (eds) Direct seeding: research issues and opportuni- ties. IRRI, Los Banos, 2002:3-14.
7Tomita S, Miyagawa S, et al. Rice yield losses by competition with weeds in rainfed paddy fields in north-east Thailand [J]. Weed Bi- olosy and Management, 2003(3 ) : 162-171.
8Hiroyuki I, Kamoshita A, et al. Assessment of management of di- rect seeded rice production under different water conditions in Cambodia[J]. Paddy Water Environ, 2008(6):91-103.
9Rezaul S M, Karim B M, Ismail B S. Weed problems and their management in rice fields of Malaysia: An overview[J]. Weed Biol- ogy and Management, 2004(4) : 177-186.