Kitthawee, Udomsak. 2016. “THE UPGRADE OF GRILLED SWINE COST FOR SUSTAINABLE DEVELOPMENT IN SAMPHRAN DISTRICT, NAKHON PATHOM PROVINCE”. Journal of Graduate School Sakon Nakhon Rajabhat University 13 (61). Sakon Nakhon, Thailand:165-72. https://so02.tci-thaijo.org/index.php/SNGSJ/article/view/59258.