Perhaps you should try some spelling variations:
khien bang » khien dong
hanh trung » thanh trung, hanh trang, manh trung
thanh tung » thanh cong
nhung cong » dung cong, thong cong, hang cong
cong ngang » cong nhan, cong quang, cong lang
ngang khan » ngan han
vap nhung » va nhung, ve nhung, voi nhung
khan cap » khan ap, than cap, khoan cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((khien bang) OR (phien ban)) - ((hanh trung) or (thanh tung)) vap nhung cong ngang khan cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((khien bang) OR (phien ban)) - ((hanh trung) OR (thanh tung)) vap nhung cong ngang khan cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((khien bang) OR (phien ban)) - ((hanh trung) or (thanh tung)) vap nhung cong ngang khan cap".
• Adding a wildcard symbol may retrieve word variants: hoc ((khien bang) OR (phien ban)) - ((hanh trung) or (thanh tung)) vap nhung cong ngang khan cap*.