PSYCHOLOGICAL DIFFICULTIES IN THE STUDY OF ETHNIC MINORITY STUDENTS: A SURVEY OF THE BOARDING ETHNIC HIGH SCHOOL IN SINH PHINH COMMUNE, TUA CHUA DISTRICT, DIEN BIEN PROVINCE. - Linh, Le Thuy; Tien, Nguyen Minh; Hao, Duong Thanh (International Journal of Advance Research and Innovative Ideas In Education, 2023)