Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
chieu sang » chieu sach, chieu xanh, hieu lang
hanh trinh » canh tranh, hanh chinh
vat nhung » vap nhung, vai nhung, ve nhung
cong san » cong tac
san toan » van toan, dan toan, manh toan
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 (chieu sang)) - hanh trinh ((vat nhung) OR (va nhung)) cong san toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu khang) OR (chieu sang)) - hanh trinh ((vat nhung) OR (va nhung)) cong san toan tap*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu khang) or (chieu sang)) - hanh trinh ((vat nhung) OR (va nhung)) cong san toan tap*".