Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
tran thuat » trong thuat, trien thuat, tran thuy
cong thanh » dong thanh, cong trinh, truong thanh
hoc thieu » toc thieu, hoc hien
tran tuan » tran xuan, tran quang, tran thanh
cong tan » cong tac, cong san, cong ty
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 ((tran thuat) OR (tran tuan)) nhung ((cong tan) or (cong thanh)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - hanh ((tran thuat) OR (tran tuan)) nhung ((cong tan) OR (cong thanh)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sang - hanh ((tran thuat) OR (tran tuan)) nhung ((cong tan) or (cong thanh)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - hanh ((tran thuat) OR (tran tuan)) nhung ((cong tan) or (cong thanh)) toan cau*.