Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
trinh va » trinh van, trinh vat, trinh vi
trinh ve » trinh he, trinh vi, trinh viet
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap
ha tinh » may tinh
va tinh » may tinh

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

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