Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hanh tranh » canh tranh, hanh trinh, hanh trang
ho chieu » theo chieu, hoc thieu, doi chieu
doc hieu » toc thieu, hoc thieu, hoc hien
tranh va » tranh van, trang va, trinh va
dan toan » dan than, manh toan, xuan toan
van toan » van tuan, van tan, van thanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) or (doc hieu)) sach - hanh tranh va nhung cong ((dan toan) or (van toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doc hieu)) sach - hanh tranh va nhung cong ((dan toan) OR (van toan)) cau.
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (doc hieu)) sach - hanh tranh va nhung cong ((dan toan) or (van toan)) cau*.