Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
hieu sang » chieu sang, hieu lang, hieu quang
tranh cua » doanh cua, manh cua
cua nhung » va nhung
cong lang » cong vang, cong luong, cong quang
doc hieu » toc thieu, hoc thieu, hoc hien
cong van » cong vang, cong san, song van
toan tap » toan 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 sang - hanh tranh cua nhung ((cong van) or (cong lang)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - hanh tranh cua nhung ((cong van) OR (cong lang)) toan tap.
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - hanh tranh cua nhung ((cong van) or (cong lang)) toan tap*.