Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
thanh vi » hanh vi, thanh va, thanh ve
cuu thuc » cuu tac
tu sach » thu sach, su sach, te sach
ky tang » ky nang, kho tang, ky trong
ky dang » ky nang, ky danh
ha hoi » hoa hoi, ha noi, xa hoi
xac va » tac va, ac va, bac va
vi cuu » vi luu, vinh cuu

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