Perhaps you should try some spelling variations:
thanh de » hanh de, thanh ve, thanh do
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » sang ma, nang cao, mang may
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
luc va » tuc va, loc va
de cua » le cua, te cua, dieu cua

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 ((nang ma) or (tang ma)) hoi. hieu ve cam ((luc va) or (duc va)) thanh de cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (tang ma)) hoi. hieu ve cam ((luc va) OR (duc va)) thanh de cua vat.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) or (tang ma)) hoi. hieu ve cam ((luc va) or (duc va)) thanh de cua vat*.