Perhaps you should try some spelling variations:
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
luan nang » luan van, van nang, luan san
luong tap » luong tai, cuong tap, luong tham
anh dung » anh dong, anh huong, sach dung
cong tap » cuong tap, cong tac, cong tan
toan tap » toan ban

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 sang) or (hieu lang)) - anh dung luan nang ((cong tap) or (luong tap)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu lang)) - anh dung luan nang ((cong tap) OR (luong tap)) toan tap.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu lang)) - anh dung luan nang ((cong tap) or (luong tap)) toan tap*.