Perhaps you should try some spelling variations:
lang trong » dung trong, cong trong, dong trong
chieu sach » chinh sach, chiet tach, chieu sang
hieu lang » chieu sang, hieu quang, nhieu tang
quang lua » quang cua, quang tuan, quang xuan
trong can » trong canh, trong chan, trong cac
lua lang » cua lang, dua lang, lua sang
can van » cac van, can ban, tan 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 sach)) - tinh quang lua lang trong can van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu lang) OR (chieu sach)) - tinh quang lua lang trong can van ban.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu lang) or (chieu sach)) - tinh quang lua lang trong can van ban*.