Perhaps you should try some spelling variations:
duong trong » dung trong
khien bang » phien ban, khien dong
thanh tran » thanh trang, thanh toan, thanh tra
hien sang » hien trang, chieu sang, thien bang
tran tuan » tran xuan, tran quang, tran thanh
dung cong » dung trong
van toan » van tuan, van tan, van thanh
toan cau » 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 ((hien sang) or (khien bang)) - thanh tran tuan ((dung cong) or (duong trong)) van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sang) OR (khien bang)) - thanh tran tuan ((dung cong) OR (duong trong)) van toan cau*.