Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
cua viet » ca viet, hoa viet, cua vat
sach ky » sac ky, sach y, sach ty
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
vu sach » vu bach, su sach, vu khach
hieu le » hieu ve, hieu he, hieu ly
dai hoi » dai hoc, dai hai, dai moi
mai hoi » mai khoi, lai hoi, mai doi
va thu » va thuc, van thu, va tu
thu va » thuc va, thue va, tu va
di cua » dai cua, doi cua, de cua

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 ky nang ((mai hoi) OR (dai hoi)). ((hieu le) or (hieu hien)) va thu va hanh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang ((mai hoi) OR (dai hoi)). ((hieu le) OR (hieu hien)) va thu va hanh di cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang ((mai hoi) OR (dai hoi)). ((hieu le) or (hieu hien)) va thu va hanh di cua viet".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang ((mai hoi) OR (dai hoi)). ((hieu le) or (hieu hien)) va thu va hanh di cua viet*.