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 van » hieu va, thien van, lieu va
van giao » nang giao, toan giao, dan gian
vu sach » vu bach, su sach, vu khach
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: vu sach doi khang xa hoi. hieu van giao duc ((va hanh) or (ban thanh)) hai dan thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach doi khang xa hoi. hieu van giao duc ((va hanh) OR (ban thanh)) hai dan thiet.
• Adding a wildcard symbol may retrieve word variants: vu sach doi khang xa hoi. hieu van giao duc ((va hanh) or (ban thanh)) hai dan thiet*.