Perhaps you should try some spelling variations:
hanh truong » hanh trong, anh truong, manh truong
truong quan » trong quan, thong quan, luong quan
thieu sang » chieu sang, thieu khang, thieu quang
hieu lang » chieu sang, hieu quang, nhieu tang
dong cong » duong cong, dang cong, cong cong
dung cong » dung trong
manh toan » thanh toan, anh tuan, tinh 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 (hieu lang)) - hanh truong quan ((dong cong) OR (dung cong)) manh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (hieu lang)) - hanh truong quan ((dong cong) OR (dung cong)) manh toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (hieu lang)) - hanh truong quan ((dong cong) OR (dung cong)) manh toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (hieu lang)) - hanh truong quan ((dong cong) OR (dung cong)) manh toan cau*.