Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
ban hanh » ban hang
chat tuc » chat xuc, luat tuc, chat huu
tu sach » su sach, te sach, tu cach
ve chat » va chat, van chat
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
vai va » mai va, dai va, hai va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ky tang xa hoi. hieu ve chat tuc ((va hanh) or (ban hanh)) vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky tang xa hoi. hieu ve chat tuc ((va hanh) OR (ban hanh)) vai va thiet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky tang xa hoi. hieu ve chat tuc ((va hanh) or (ban hanh)) vai va thiet*.