Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
dan thiet » luan thiet, toan thiet, doan thien
sach doi » sach hoi, sach moi, sach dao
khang xa » khang a, hang ca, lang xa
hieu dan » hieu van, sieu dan, hieu dac
gian duc » giao duc, gia duc, gian dac
su sach » so sach, vu sach
va hanh » van hanh, va thanh, va danh
hai dan » hai dang, hoi dan, hai tan

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach doi khang xa hoi. hieu dan gian duc ((va hanh) or (ban thanh)) hai dan thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach doi khang xa hoi. hieu dan gian duc ((va hanh) OR (ban thanh)) hai dan thiet.
• Adding a wildcard symbol may retrieve word variants: su sach doi khang xa hoi. hieu dan gian duc ((va hanh) or (ban thanh)) hai dan thiet*.