Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, diep quang
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
trinh cua » tinh cua, trinh luat, trinh quan
cua nhung » va nhung
dan than » dan chan, ban than, dan toan
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: hoi ((hieu quang) or (hieu qua)) - hanh trinh cua nhung cong ((dan than) or (van than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi ((hieu quang) OR (hieu qua)) - hanh trinh cua nhung cong ((dan than) OR (van than)) cao.
• Adding a wildcard symbol may retrieve word variants: hoi ((hieu quang) or (hieu qua)) - hanh trinh cua nhung cong ((dan than) or (van than)) cao*.