Sittivoradet P, Suntivarakorn R. An appropriate approach for biogas production and utilization from waste food and animal manure in Khon Kaen University. Eng Appl Sci Res [internet]. 2013 May 15 [cited 2025 Apr. 10];40(1):35-46. available from: https://ph01.tci-thaijo.org/index.php/easr/article/view/8565