Punnatut Wongsasan และ Pramuk Osiri. (2015) Injury and musculoskeletal problem reduction of roller cleaning workers:a case study of a hygienic plastic film manufactuer. Mahidol University:ม.ป.ท.Punnatut Wongsasan และ Pramuk Osiri. 2015. Injury and musculoskeletal problem reduction of roller cleaning workers:a case study of a hygienic plastic film manufactuer. ม.ป.ท.:Mahidol University;Punnatut Wongsasan และ Pramuk Osiri. Injury and musculoskeletal problem reduction of roller cleaning workers:a case study of a hygienic plastic film manufactuer. ม.ป.ท.:Mahidol University, 2015. Print.