Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
lang trong » dung trong, cong trong, dong trong
hieu lang » chieu sang, hieu quang, nhieu tang
tinh quan » tinh quang, trinh quan, tin quan
quan lua » quan luan, quan cua, quang cua
lua lang » cua lang, dua lang, lua sang
trong ca » trong cac, trong nha
ca luan » cu luan, ca lua, ca quan

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)) - tinh quan lua lang trong ca luan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu lang) OR (chieu sach)) - tinh quan lua lang trong ca luan van.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu lang) or (chieu sach)) - tinh quan lua lang trong ca luan van*.