Perhaps you should try some spelling variations:
hanh trinh » hanh chinh
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
dung cong » dung trong
van thanh » ban thanh, van tuan
thanh cao » thanh ca, thanh cac, thanh thao
qua dung » quang dung, su dung, qua song
cong van » cong vang, cong san, song van

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu lang) OR (chieu sang)) - ((hanh trinh) or (canh tranh)) qua dung cong van thanh cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (chieu sang)) - ((hanh trinh) OR (canh tranh)) qua dung cong van thanh cao*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) OR (chieu sang)) - ((hanh trinh) or (canh tranh)) qua dung cong van thanh cao*".