Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
thanh vi » hanh vi, thanh ve, nhanh vi
thanh va » thanh van, hanh va, thanh ha
cuu thuc » cuu tac
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
xac va » tac va, ac va, bac va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky lang xa hoi. hieu qua cham ((xac va) or (duc va)) ((thanh vi) OR (thanh va)) cuu thuc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. hieu qua cham ((xac va) OR (duc va)) ((thanh vi) OR (thanh va)) cuu thuc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. hieu qua cham ((xac va) or (duc va)) ((thanh vi) OR (thanh va)) cuu thuc".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu qua cham ((xac va) or (duc va)) ((thanh vi) OR (thanh va)) cuu thuc*.