Perhaps you should try some spelling variations:
ban hanh » ban hang
cham tu » pham tu, cam tu, chai tu
hieu tu » chieu tu, hieu tuc, hien tu
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
lang ha » long ha
tu cham » toc cham, thi cham
tu ban » thu ban, te ban
vi cau » va cau, di cau, viet cau
ve cau » ke cau, va cau, ve cac

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 y ((nang xa) or (lang ha)) hoi. hieu tu cham tu ban hanh ((vi cau) OR (ve cau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (lang ha)) hoi. hieu tu cham tu ban hanh ((vi cau) OR (ve cau)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) or (lang ha)) hoi. hieu tu cham tu ban hanh ((vi cau) OR (ve cau)) tren".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) or (lang ha)) hoi. hieu tu cham tu ban hanh ((vi cau) OR (ve cau)) tren*.