Perhaps you should try some spelling variations:
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
dang xay » dang van, van xay
so sach » so sanh, bo sach, co sach
cau luc » cau truc, cau phuc
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
ve cau » ke cau, va cau, ve cac
ang xa » lang xa, mang xa, hoang xa
du cua » duy cua, dau cua, dum cua
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty ((ang xa) OR (dang xay)) hoi. hieu ve cau luc ((van hanh) or (ban hanh)) du cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((ang xa) OR (dang xay)) hoi. hieu ve cau luc ((van hanh) OR (ban hanh)) du cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((ang xa) OR (dang xay)) hoi. hieu ve cau luc ((van hanh) or (ban hanh)) du cua te".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((ang xa) OR (dang xay)) hoi. hieu ve cau luc ((van hanh) or (ban hanh)) du cua te*.