Understanding perception and drivers to change food safety condition of pork value chain actors: The view of slaughterhouse owners and pork retailers in northern Vietnam - Hai Hoang Tuan Ngo; Phuc Pham-Duc; Luong Nguyen Thanh; Sinh Dang-Xuan; Hung Nguyen-Viet; Hung Pham Van; Nga Nguyen Thi Duong; Huyen Nguyen, Thi-Thu; Grace, Delia; Unger, Fred (2021)