Perhaps you should try some spelling variations:
khien bang » phien ban, khien dong
hien sang » hien trang, chieu sang, thien bang
hanh tran » hanh trang, thanh tran, hanh tram
van dang » van dong, van nang, van dan
van dung » van dong, xay dung, tin dung
cong van » cong vang, cong san, song van
van tuan » van quan, van ban, anh tuan
tuan tap » toan tap, tuan tai, tuyen 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)) - hanh tran ((van dang) or (van dung)) cong van tuan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sang) OR (khien bang)) - hanh tran ((van dang) OR (van dung)) cong van tuan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien sang) OR (khien bang)) - hanh tran ((van dang) or (van dung)) cong van tuan tap".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien sang) OR (khien bang)) - hanh tran ((van dang) or (van dung)) cong van tuan tap*.