Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
trinh quan » trinh han
dang trong » dung trong, dong trong, lang trong
hoc thieu » toc thieu, hoc hien
cong toan » cong tan, cong hoan, cong tuan
toan ban » van ban
luat » luan, xuat

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 ((trinh luat) OR (((trinh quan) OR (tinh quang)))) dang trong cong toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sang - hanh ((trinh luat) or (((trinh quan) OR (tinh quang)))) dang trong cong toan ban~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - hanh ((trinh luat) or (((trinh quan) OR (tinh quang)))) dang trong cong toan ban*.