Perhaps you should try some spelling variations:
thanh trung » thanh tung
hanh trung » hanh trang, manh trung, danh trung
diep quang » dinh quang
tuan thong » toan thong, tran thong, tuan phong
thong cong » trong cong, tong cong, thong thong
hieu quan » hieu qua, lieu quan, thien quan
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((diep quang) or (hieu quan)) - ((hanh trung) OR (thanh trung)) tuan thong cong san toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((diep quang) OR (hieu quan)) - ((hanh trung) OR (thanh trung)) tuan thong cong san toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((diep quang) or (hieu quan)) - ((hanh trung) OR (thanh trung)) tuan thong cong san toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((diep quang) or (hieu quan)) - ((hanh trung) OR (thanh trung)) tuan thong cong san toan cao*.