Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thieu sang » chieu sang, thieu quang, hieu lang
hanh tranh » canh tranh, hanh trang, lanh tranh
hanh trinh » canh tranh, hanh chinh
va trong » va truong, va thong, va tuong
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan ban » van 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 sang) OR (thieu khang)) - ((hanh tranh) or (hanh trinh)) va trong cong dan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu khang)) - ((hanh tranh) OR (hanh trinh)) va trong cong dan toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) OR (thieu khang)) - ((hanh tranh) or (hanh trinh)) va trong cong dan toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) OR (thieu khang)) - ((hanh tranh) or (hanh trinh)) va trong cong dan toan ban*.