Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
tran van » luan van
cong van » cong vang, cong san, song van
tran va » trang va, tranh va, toan va
van tan » van tuan, van ban, van tai
tan tap » toan tap, han tap, tan tat

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

• Performing a fuzzy search may retrieve terms with similar spellings: nghe hieu lang - thanh ((tran va) OR (tran van)) nhung cong van tan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "nghe hieu lang - thanh ((tran va) OR (tran van)) nhung cong van tan tap".
• Adding a wildcard symbol may retrieve word variants: nghe hieu lang - thanh ((tran va) OR (tran van)) nhung cong van tan tap*.