Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thieu sang » chieu sang, thieu quang, hieu lang
nhung cong » dung cong, thong cong, hang cong
toan thanh » tran thanh, hoan thanh, toan thang
tuong cua » truong cua, huong cua, thong cua
cong toan » cong tan, cong hoan, cong tuan
thanh cap » thanh lap, hanh cap, than cap
tung cua » trung cua, dung cua, tang cua

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