Perhaps you should try some spelling variations:
khang cong » hang cong, thanh cong, dang cong
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
hanh luan » khanh luan, hang luan, hanh luat
van khang » van khanh, van thanh, van quang
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu lang) or (chieu sang)) - hanh luan van khang cong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (chieu sang)) - hanh luan van khang cong tap toan cau.
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (chieu sang)) - hanh luan van khang cong tap toan cau*.