Perhaps you should try some spelling variations:
su sach » so sach, vu sach
lai hoi » dai hoi, lai hoa, lai roi
cua tre » cua te, cua triet, dua tren
sach ky » sac ky, sach y, sach ty
qua bac » qua ban, qua cac, cua bac
cuu tre » cau tren, cau treo
ma hoi » mai hoi, xa hoi, ma hoa
va anh » van anh, va danh, va hanh
anh va » hanh va
bo va » bao va, do va, so va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang ((ma hoi) or (lai hoi)). hieu qua bac bo va anh va ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((ma hoi) OR (lai hoi)). hieu qua bac bo va anh va ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((ma hoi) or (lai hoi)). hieu qua bac bo va anh va ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((ma hoi) or (lai hoi)). hieu qua bac bo va anh va ((cua tre) OR (cuu tre))*.