Perhaps you should try some spelling variations:
nhung cong » thong cong, hang cong, nhung don
trinh vat » trinh van, trinh luat, sinh vat
dung cong » dung trong
trinh va » trinh van, trinh ve, trinh vi
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap
o may » co may, bo may, do may

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

• Performing a fuzzy search may retrieve terms with similar spellings: o may tinh - hanh ((trinh va) or (trinh vat)) ((nhung cong) OR (dung cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: o may tinh - hanh ((trinh va) OR (trinh vat)) ((nhung cong) OR (dung cong)) dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "o may tinh - hanh ((trinh va) or (trinh vat)) ((nhung cong) OR (dung cong)) dan toan cao".
• Adding a wildcard symbol may retrieve word variants: o may tinh - hanh ((trinh va) or (trinh vat)) ((nhung cong) OR (dung cong)) dan toan cao*.