Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
doi chiet » doi chieu, doi chi, doi chinh
hanh tang » hanh trang, anh tang, hanh tung
hanh mang » nhanh mang, hanh trang, nhanh lang
doi viet » dai viet, hoi viet, oi viet
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chiet) OR (doi viet)) tach - ((hanh tang) OR (hanh mang)) va nhung cong tac toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chiet) OR (doi viet)) tach - ((hanh tang) or (hanh mang)) va nhung cong tac toan cau~".
• Adding a wildcard symbol may retrieve word variants: ((doi chiet) OR (doi viet)) tach - ((hanh tang) or (hanh mang)) va nhung cong tac toan cau*.