Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
hieu lang » chieu sang, hieu quang, nhieu tang
vat nhung » va nhung, vai nhung, ve nhung
vap nhung » va nhung, ve nhung, voi nhung
duong van » duong va, luong va, dang van
van toan » van tuan, van tan, van thanh
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu khang) or (hieu lang)) - canh tranh ((vat nhung) OR (vap nhung)) duong van toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu khang) OR (hieu lang)) - canh tranh ((vat nhung) OR (vap nhung)) duong van toan tap*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu khang) or (hieu lang)) - canh tranh ((vat nhung) OR (vap nhung)) duong van toan tap*".