Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
hanh trinh » hanh chinh
hoc thieu » toc thieu, hoc hien
qua dung » quang dung, su dung, qua song
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan cau » toan cao, toan ban, toan tap

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 - ((hanh trinh) or (canh tranh)) qua dung ((cong dan) or (cong san)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - ((hanh trinh) OR (canh tranh)) qua dung ((cong dan) OR (cong san)) toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - ((hanh trinh) or (canh tranh)) qua dung ((cong dan) or (cong san)) toan cau*.