Perhaps you should try some spelling variations:
thanh vi » hanh vi, thanh va, thanh ve
sach ky » sac ky, sach y, sach ty
qua hai » qua hoat
tu sach » thu sach, su sach, te sach
tang xa » trang xa, lang xa, tang ha
tang ma » mang may, tang van
cuu tac » cuu dac, cuu cac, cuu xac
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 xa) OR (tang ma)) hoi. hieu qua hai ((xac va) or (duc va)) thanh vi cuu tac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((tang xa) OR (tang ma)) hoi. hieu qua hai ((xac va) OR (duc va)) thanh vi cuu tac.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((tang xa) OR (tang ma)) hoi. hieu qua hai ((xac va) or (duc va)) thanh vi cuu tac".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((tang xa) OR (tang ma)) hoi. hieu qua hai ((xac va) or (duc va)) thanh vi cuu tac*.