Sagutray Simangunsong R. Analysis of Factors Affecting Work Productivity of Tea Pickers at the Tea and Quinine Research Center, Simalungun Regency . JARUDA [Internet]. 2022 Aug. 21 [cited 2024 Nov. 27];1(1):37-42. Available from: http://jaruda.org/index.php/go/article/view/5