Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
hanh tang » hanh trang, anh tang, hanh mang
tang luan » dung luan
luan ban » luan van, luan san, luan han
ban cong » bang cong, van cong, phan cong
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: hoc ((hieu lang) or (hieu quang)) - hanh tang luan ban cong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu lang) OR (hieu quang)) - hanh tang luan ban cong tap toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu lang) or (hieu quang)) - hanh tang luan ban cong tap toan cau*.