Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thieu sang » chieu sang, thieu quang, hieu lang
nhung cong » thong cong, hang cong, nhung don
canh manh » lanh manh, canh tranh, cach mang
dung cong » dung trong
manh cua » doanh cua, ban cua
tan toan » tan tran, tap toan, van toan
toan cau » 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)) - canh manh cua ((nhung cong) or (dung cong)) tan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu khang)) - canh manh cua ((nhung cong) OR (dung cong)) tan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) OR (thieu khang)) - canh manh cua ((nhung cong) or (dung cong)) tan toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) OR (thieu khang)) - canh manh cua ((nhung cong) or (dung cong)) tan toan cau*.