Perhaps you should try some spelling variations:
trung thanh » truong thanh
sang trung » dang trung, san trung, lang trung
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
quang qua » quang cua, quang tuan, quang xuan
thanh van » thanh san, thanh toan, thanh phan
qua sang » qua song, qua san, bua sang

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((chieu sang) or (hieu lang)) - tinh quang qua sang trung thanh van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((chieu sang) OR (hieu lang)) - tinh quang qua sang trung thanh van ban*.