Perhaps you should try some spelling variations:
cua viet » ca viet, cua vat, cua dieu
vu sach » vu bach, su sach, vu khach
ty nang » ky nang, ty xang, ty hang
cao hoi » cau hoi, co hoi, cao hoc
hieu le » hieu ve, hieu ly, tieu le
hieu he » hieu ve, hiem he, hieu hien
sach ty » sach y, sach tu, sach thu
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
na thu » nam thu, va thu, ma thu
thu va » thuc va, thue va, tu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ty nang cao hoi. ((hieu le) or (hieu he)) na thu va hanh di ((cua viet) OR (hoa viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty nang cao hoi. ((hieu le) OR (hieu he)) na thu va hanh di ((cua viet) OR (hoa viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty nang cao hoi. ((hieu le) or (hieu he)) na thu va hanh di ((cua viet) OR (hoa viet))".
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang cao hoi. ((hieu le) or (hieu he)) na thu va hanh di ((cua viet) OR (hoa viet))*.