Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thieu sang » chieu sang, thieu quang, hieu lang
hanh tranh » canh tranh, hanh trinh, hanh trang
cua thuong » cua truong, cua phuong, ca thuong
tranh cua » doanh cua, manh cua
luong cao » luong dao, luong cho, truong cao
luong cac » luong cuoc, luong va, luong tai
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) or (thieu khang)) - hanh tranh cua thuong ((luong cao) OR (luong cac)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu khang)) - hanh tranh cua thuong ((luong cao) OR (luong cac)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (thieu khang)) - hanh tranh cua thuong ((luong cao) OR (luong cac)) toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (thieu khang)) - hanh tranh cua thuong ((luong cao) OR (luong cac)) toan cao*.