Somsak Sriwanichapoom. 1995. Catalytic hydrotreatment of used lubricating oil. Bangkok:Chulalongkorn University;
Somsak Sriwanichapoom. (1995) Catalytic hydrotreatment of used lubricating oil (รายงานผลงานวิจัย). Chulalongkorn University:Bangkok.
Somsak Sriwanichapoom. Catalytic hydrotreatment of used lubricating oil. Bangkok:Chulalongkorn University, 1995.
Somsak Sriwanichapoom. (1995) Catalytic hydrotreatment of used lubricating oil (รายงานผลงานวิจัย). Chulalongkorn University:Bangkok.