Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, diep quang
hanh tran » hanh trang, thanh tran, hanh tram
lang cong » dang cong, hang cong, lang dong
bang cong » dang cong, bang song, hang cong
tran van » luan van
san phan » san pham, van phan, sat phan
phan cau » phan dau, phan cac, phan tu

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 quang) or (hieu qua)) - hanh tran van ((lang cong) OR (bang cong)) san phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu quang) OR (hieu qua)) - hanh tran van ((lang cong) OR (bang cong)) san phan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu quang) or (hieu qua)) - hanh tran van ((lang cong) OR (bang cong)) san phan cau".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quang) or (hieu qua)) - hanh tran van ((lang cong) OR (bang cong)) san phan cau*.