Perhaps you should try some spelling variations:
ban thanh » ban hang
van thiet » va thiet, dan thiet, can thiet
sach doi » sach hoi, sach moi, sach dao
doi xang » doi mang, doi khang, doi song
ban hanh » ban hang
su sach » so sach, vu sach
xang xa » lang xa, mang xa, ang xa
hieu va » lieu va, hieu qua
va giao » van giao, va giai, va gia
hai van » thai van, ha van, 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 xang xa hoi. hieu va giao duc ((ban hanh) or (ban thanh)) hai van thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach doi xang xa hoi. hieu va giao duc ((ban hanh) OR (ban thanh)) hai van thiet.
• Adding a wildcard symbol may retrieve word variants: su sach doi xang xa hoi. hieu va giao duc ((ban hanh) or (ban thanh)) hai van thiet*.