Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
nhieu tang » chieu sang, nhiet nang
hieu lang » chieu sang, hieu quang, hieu van
hang tai » hang va, dung tai
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan cao » toan ban, toan tap
hang ca » hang va, nang cao, hang dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((hieu lang) or (nhieu tang)) - hanh ((hang ca) OR (hang tai)) nhung cong tan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hieu lang) OR (nhieu tang)) - hanh ((hang ca) OR (hang tai)) nhung cong tan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hieu lang) or (nhieu tang)) - hanh ((hang ca) OR (hang tai)) nhung cong tan toan cao".
• Adding a wildcard symbol may retrieve word variants: theo ((hieu lang) or (nhieu tang)) - hanh ((hang ca) OR (hang tai)) nhung cong tan toan cao*.