Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
vat phuong » va phuong, van phuong, viet phuong
hoc thieu » toc thieu, hoc hien
hanh sinh » hanh tinh, hanh dinh, hinh sinh
cong van » cong vang, song van, cong tan
cong san » cong tac
toan ban » van ban

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 sinh vat phuong ((cong van) OR (cong san)) ((toan tap) OR (toan ban))~.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - hanh sinh vat phuong ((cong van) or (cong san)) ((toan tap) or (toan ban))*.