Perhaps you should try some spelling variations:
danh vai » danh sai, danh va, doanh van
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
vai cua » dai cua, hai cua, lai cua
tai hoi » tai khoi, dai hoi, tai hai
hieu ve » hieu va, hieu van
tai roi » lai roi, tai loi, toan roi
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa

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 ((tai roi) or (tai hoi)). hieu ve cam ((luc va) OR (tuc va)) danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((tai roi) OR (tai hoi)). hieu ve cam ((luc va) OR (tuc va)) danh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((tai roi) or (tai hoi)). hieu ve cam ((luc va) OR (tuc va)) danh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((tai roi) or (tai hoi)). hieu ve cam ((luc va) OR (tuc va)) danh vai cua tre*.