Perhaps you should try some spelling variations:
nhung cong » thong cong, hang cong, nhung don
trinh san » trinh quan, trinh toan, trinh luan
trinh han » trinh quan
dung cong » dung trong
chi xanh » chi anh, chi danh, chi hanh
san toan » van toan, dan toan, manh toan
toan cau » toan cao, toan ban, toan tap
doi chi » doi khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chi xanh - ((trinh san) OR (trinh han)) quan ((nhung cong) or (dung cong)) san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chi xanh - ((trinh san) OR (trinh han)) quan ((nhung cong) OR (dung cong)) san toan cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chi xanh - ((trinh san) OR (trinh han)) quan ((nhung cong) or (dung cong)) san toan cau*".