Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hieu sang » chieu sang, hieu lang, hieu quang
trinh cua » tinh cua, trinh luat, trinh quan
cua trong » cua truong, cua trung, qua trong
doc hieu » toc thieu, hoc thieu, hoc hien
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu sang - hanh trinh cua trong ((cong tan) or (cong san)) van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - hanh trinh cua trong ((cong tan) OR (cong san)) van ban*.