Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
lang trong » dung trong, cong trong, dong trong
hieu lang » chieu sang, hieu quang, nhieu tang
tinh quan » tinh quang, trinh quan, tin quan
trong tan » trong quan, trong cac, trong ca
quan lua » quan luan, quan cua, quang cua
lua lang » cua lang, dua lang, lua sang
tran van » luan van

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