Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
sach tu » sach thu, cach tu, sach ty
hieu ve » hieu va, hieu van
cau tre » cau tren, cau treo, cau tra
nang xa » lang xa, nang ma, mang xa
va dau » va dao
va cau » van cau, va cac, va cao
ve cac » va cac, vien cac
cac o » cac co, cac bo, cac ho

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 tu ((nang xa) or (nang x)) hoi. hieu ve cac o ((va hanh) or (va dau)) va cau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu ((nang xa) OR (nang x)) hoi. hieu ve cac o ((va hanh) OR (va dau)) va cau tre.
• Adding a wildcard symbol may retrieve word variants: tu sach tu ((nang xa) or (nang x)) hoi. hieu ve cac o ((va hanh) or (va dau)) va cau tre*.