Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
hanh luan » khanh luan, hang luan, hanh luat
dang cong » dung cong
van dang » van dong, van dung, van nang
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
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 dang cong bai toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (chieu sang)) - hanh luan van dang cong bai toan cau.
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (chieu sang)) - hanh luan van dang cong bai toan cau*.