Perhaps you should try some spelling variations:
cac triet » cac thiet, cac trieu, cau triet
ban thanh » ban hanh, ban hang
hieu quan » hieu qua, lieu quan, thien quan
thanh ve » hanh ve, thanh va, thanh vien
quoc ban » quoc bao, quoc lan, quoc quan
nam quoc » nam duoc, nam buoc, nam thuoc
quan nam » quang nam, xuan nam, quan am
tu sach » thu sach, su sach, tu cach
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
te sach » toc sach
ve cac » va cac, vien 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) or (te sach)) ly ((nang xa) or (nang ma)) hoi. hieu quan nam quoc ban thanh ve cac triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ly ((nang xa) OR (nang ma)) hoi. hieu quan nam quoc ban thanh ve cac triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ly ((nang xa) or (nang ma)) hoi. hieu quan nam quoc ban thanh ve cac triet*.