Perhaps you should try some spelling variations:
khien tinh » thien tinh, khien thich, bien tinh
hanh tranh » canh tranh, hanh trinh, hanh trang
nhung cong » dung cong, thong cong, hang cong
hien tinh » thien tinh, bien tinh, dien tinh
manh toan » thanh toan, anh tuan, tinh toan
tranh va » tranh van, trang va, trinh va
van than » van thanh, van thang, van tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hien tinh) OR (khien tinh)) - hanh tranh va nhung cong ((manh toan) or (van than)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien tinh) OR (khien tinh)) - hanh tranh va nhung cong ((manh toan) OR (van than)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien tinh) OR (khien tinh)) - hanh tranh va nhung cong ((manh toan) or (van than)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien tinh) OR (khien tinh)) - hanh tranh va nhung cong ((manh toan) or (van than)) cau*.