Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hieu lang » chieu sang, hieu quang, nhieu tang
van khang » van khanh, van thanh, van quang
doc hieu » toc thieu, hoc thieu, hoc hien
van hang » van hoang, van thang, ban hang
cong tan » cong tac, cong san, cong thanh
toan cau » toan cao, toan tap, toan tai
toan ban » van ban

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 lang - hanh trinh ((van hang) or (van khang)) cong tan ((toan cau) or (toan ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu lang - hanh trinh ((van hang) OR (van khang)) cong tan ((toan cau) OR (toan ban)).
• Adding a wildcard symbol may retrieve word variants: doc hieu lang - hanh trinh ((van hang) or (van khang)) cong tan ((toan cau) or (toan ban))*.