Perhaps you should try some spelling variations:
thanh vi » hanh vi, thanh va, thanh ve
tu sach » thu sach, su sach, te sach
tang ma » tang van
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
do van » dao van, vo van, so van
vi cua » vai cua, di cua
ve cam » ve cham, ve cac, va cam
cua te » cua tu
o van » vo van, so van, ho van

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 ((mang may) or (tang ma)) hoi. hieu ve cam ((o van) OR (do van)) thanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((mang may) OR (tang ma)) hoi. hieu ve cam ((o van) OR (do van)) thanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((mang may) or (tang ma)) hoi. hieu ve cam ((o van) OR (do van)) thanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((mang may) or (tang ma)) hoi. hieu ve cam ((o van) OR (do van)) thanh vi cua te*.