Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
hanh tranh » canh tranh, hanh trang, lanh tranh
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
hoc thieu » toc thieu, hoc hien
cua nhung » va nhung
san toan » van toan, dan toan, manh toan

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - ((hanh tranh) OR (hanh trinh)) cua nhung cong ((san toan) OR (tinh toan)) cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sang - ((hanh tranh) OR (hanh trinh)) cua nhung cong ((san toan) or (tinh toan)) cao~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - ((hanh tranh) OR (hanh trinh)) cua nhung cong ((san toan) or (tinh toan)) cao*.