Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
thu sach » tu sach, thuat sach, thuoc sach
mai hoi » mai khoi, dai hoi, mai doi
lai hoi » dai hoi, lai hoa, lai roi
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
tuc va » thuc va, truc va, tuc xa
ve cam » ve cham, ve cac, va cam
luc va » duc va, loc va
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang ((mai hoi) or (lai hoi)). hieu ve cam ((luc va) OR (tuc va)) thanh dai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((mai hoi) OR (lai hoi)). hieu ve cam ((luc va) OR (tuc va)) thanh dai cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((mai hoi) or (lai hoi)). hieu ve cam ((luc va) OR (tuc va)) thanh dai cua tu*".