Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hanh trinh » hanh chinh
dung cong » dung trong
hoi hieu » hoi phieu, hoi tieu, moi hieu
cua dung » cua dang, cua dong, qua dung
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi hieu quang - ((hanh trinh) OR (canh tranh)) cua dung cong tap toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi hieu quang - ((hanh trinh) OR (canh tranh)) cua dung cong tap toan cao".
• Adding a wildcard symbol may retrieve word variants: hoi hieu quang - ((hanh trinh) OR (canh tranh)) cua dung cong tap toan cao*.