Perhaps you should try some spelling variations:
hanh nhanh » hanh nhan, nhanh thanh, thanh thanh
chiet tach » chieu sach
quang dung » quang trung, ung dung, cuong dung
hieu lang » chieu sang, hieu quang, nhieu tang
dung cong » dung trong
thanh ban » thanh san, thanh van, thanh bai
thanh bac » nhanh bac, thanh bai, thanh san
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: hoc ((hieu lang) or (chiet tach)) - hanh nhanh quang dung cong van ((thanh ban) OR (thanh bac))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu lang) OR (chiet tach)) - hanh nhanh quang dung cong van ((thanh ban) OR (thanh bac)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu lang) or (chiet tach)) - hanh nhanh quang dung cong van ((thanh ban) OR (thanh bac))".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu lang) or (chiet tach)) - hanh nhanh quang dung cong van ((thanh ban) OR (thanh bac))*.