Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, nhieu tang, hieu van
hanh tran » hanh trang, thanh tran, hanh tram
van thong » van thuong, van phong, va thong
tran van » luan van
cong van » cong vang, cong san, song van
van toan » van tuan, van tan, van thanh
toan ban » van ban

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 tran van thong cong van toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu lang) OR (hieu quang)) - hanh tran van thong cong van toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu lang) OR (hieu quang)) - hanh tran van thong cong van toan ban*.