Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
nhieu tang » chieu sang, hieu lang, nhiet nang
hanh hang » thanh hang, hang hang, hanh han
cong vang » cong lang, cong quang, cong ngang
cong van » cong san, song van, cong tan
va hang » van hang, va nang, va lang
tai sao » tai san

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 sach) or (nhieu tang)) - hanh hang va hang ((cong van) OR (cong vang)) tai sao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (nhieu tang)) - hanh hang va hang ((cong van) OR (cong vang)) tai sao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sach) or (nhieu tang)) - hanh hang va hang ((cong van) OR (cong vang)) tai sao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (nhieu tang)) - hanh hang va hang ((cong van) OR (cong vang)) tai sao*.