Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
dong trong » duong trong, dung trong, cong trong
hieu lang » chieu sang, hieu quang, nhieu tang
trong dan » trong dang, trong san, trong tan
tin quan » tinh quang, trinh quan, lien quan
quan lua » quan luan, quan cua, quang cua
lua dong » luan dong, luu dong, cua dong
dan than » dan chan, ban than, van than
than man » than ma, thanh san, tran manh

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu lang) or (chieu sach)) - tin quan lua dong trong dan than man~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu lang) OR (chieu sach)) - tin quan lua dong trong dan than man.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu lang) or (chieu sach)) - tin quan lua dong trong dan than man*.