Perhaps you should try some spelling variations:
thien hieu » thien nhien, thien chien, thien hue
phuong ban » phuong bang, phuong lan, phuong bac
hieu lang » chieu sang, hieu quang, nhieu tang
luan vang » luan nang, luan tang, luan va
ban khan » ban than, ban nhan, ban chan
khan cap » khan ap, than cap, khoan cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: thien hieu lang - sach dung ((luan vang) or (luan van)) phuong ban khan cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thien hieu lang - sach dung ((luan vang) OR (luan van)) phuong ban khan cap*.