Perhaps you should try some spelling variations:
trinh quang » tinh quang, trinh quan, tranh quang
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
hanh trinh » canh tranh, hanh chinh
quang dung » quang trung, ung dung, cuong dung
dung cong » dung trong
dan than » dan chan, van than, dan toan
ban than » ban thanh, van thanh, ban hang

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sang) or (chieu sach)) - hanh trinh quang dung cong ((dan than) OR (ban than)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (chieu sach)) - hanh trinh quang dung cong ((dan than) OR (ban than)) ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) or (chieu sach)) - hanh trinh quang dung cong ((dan than) OR (ban than)) ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (chieu sach)) - hanh trinh quang dung cong ((dan than) OR (ban than)) ban*.