Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
hieu lang » chieu sang, hieu quang, nhieu tang
tranh cua » doanh cua, manh cua
cong cong » cong dong, dung cong, dang cong
hoc hieu » hoc thieu, hoc hien, doc hieu
tap toan » tap doan, tap quan, bai toan
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: hoc hieu lang - hanh tranh cua ((cong cong) or (trong cong)) tap toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - hanh tranh cua ((cong cong) OR (trong cong)) tap toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - hanh tranh cua ((cong cong) or (trong cong)) tap toan ban*.