Azman, A. “NEED ASSESMENT OF SAFETY WORK SEMEN PADANG VOCATIONAL HIGH SCHOOL BASED ON SAFETY WORK IN SEMEN PADANG FACTORY”. UNES Journal of Scientech Research, Vol. 1, no. 2, Dec. 2016, pp. 28-37, https://ojs.ekasakti.org/index.php/UJSR/article/view/162.