Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
cua viet » ca viet, hoa viet, cua vat
so sach » so sanh, bo sach, co sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
cach tu » cach thuc
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
cac tu » cac thu, cac du, tac tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ly nang x ho. hieu van ((cac tu) OR (cach tu)) ((va hanh) or (ban thanh)) vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ly nang x ho. hieu van ((cac tu) OR (cach tu)) ((va hanh) OR (ban thanh)) vai cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ly nang x ho. hieu van ((cac tu) OR (cach tu)) ((va hanh) or (ban thanh)) vai cua viet*".