Aisy Rahmania. “The Risk Matrix of Occupational Health and Safety on Cleaning Service Occupation in Universitas X Ponorogo”. Medical Technology and Public Health Journal 7, no. 1 (April 26, 2023): 79–88. Accessed November 23, 2024. https://journal2.unusa.ac.id/index.php/MTPHJ/article/view/3591.