Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thieu sang » chieu sang, thieu quang, hieu lang
dong chuan » dong chan, dong thuan, dong chuyen
nhan dong » nhanh dong, nhan dang, phan dong
long cong » luong cong, cong cong, long tong
tong cong » trong cong, cong cong, dung cong
van tan » van tuan, van ban, van tai
tan cau » toan cau, van cau, tan ca

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)) - nhan dong chuan ((long cong) or (tong cong)) van tan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu khang)) - nhan dong chuan ((long cong) OR (tong cong)) van tan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) OR (thieu khang)) - nhan dong chuan ((long cong) or (tong cong)) van tan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) OR (thieu khang)) - nhan dong chuan ((long cong) or (tong cong)) van tan cau*.