Perhaps you should try some spelling variations:
viec thong » viec thuong, viet thong, viec khong
nhieu tang » chieu sang, nhiet nang
hieu lang » chieu sang, hieu quang, hieu van
canh manh » lanh manh, canh tranh, cach mang
dung cong » dung trong
manh cua » doanh cua, ban cua
cua dung » cua dang, cua dong, qua dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((nhieu tang) or (hieu lang)) - canh manh cua dung cong ((viec thong) OR (vien thong)) tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((nhieu tang) OR (hieu lang)) - canh manh cua dung cong ((viec thong) OR (vien thong)) tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((nhieu tang) or (hieu lang)) - canh manh cua dung cong ((viec thong) OR (vien thong)) tu".
• Adding a wildcard symbol may retrieve word variants: doi ((nhieu tang) or (hieu lang)) - canh manh cua dung cong ((viec thong) OR (vien thong)) tu*.