Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
hanh tranh » canh tranh, hanh trinh, hanh trang
nhung cong » dung cong, thong cong, hang cong
van thanh » ban thanh, van tuan
doc hieu » toc thieu, hoc thieu, hoc hien
tranh va » tranh van, trang va, trinh va
dan toan » van toan, dan than, manh toan
van than » van thang, van tuan, van phan

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 nganh - hanh tranh va nhung cong ((((dan toan) or (van thanh))) or (van than)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu nganh - hanh tranh va nhung cong ((((dan toan) OR (van thanh))) OR (van than)) cau.
• Adding a wildcard symbol may retrieve word variants: doc hieu nganh - hanh tranh va nhung cong ((((dan toan) or (van thanh))) or (van than)) cau*.