Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dai nang » da nang, dai dang, dai thang
cao nang » cao dang, cam nang, cao tang
danh dai » danh dau, danh di, danh sai
va triet » va thiet, va trien, ve triet
qua hai » qua hoat
hai duc » hoai duc, mai duc, ha duc
va danh » va dinh, va dan, va hanh
dai va » mai va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ((dai nang) or (cao nang)) xa hoi. hieu qua hai duc va danh dai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((dai nang) OR (cao nang)) xa hoi. hieu qua hai duc va danh dai va triet.
• Adding a wildcard symbol may retrieve word variants: hoc sach ((dai nang) or (cao nang)) xa hoi. hieu qua hai duc va danh dai va triet*.