Perhaps you should try some spelling variations:
thiet ngan » hiem ngan, thien nga, thien nhan
hanh tang » hanh trang, anh tang, hanh mang
dung cong » dung trong
cong doan » cong dan, cong hoan, dong doanh
thi ngan » thu ngan, thi nga, tri ngan
tang cua » mang cua, hang cua, tang luan
cua dung » cua dang, cua dong, qua dung
doan van » doan va, hoang van, luan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thiet ngan) or (((thi ngan) OR (tai ngan)))) - hanh tang cua dung cong doan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet ngan) OR (((thi ngan) OR (tai ngan)))) - hanh tang cua dung cong doan van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet ngan) or (((thi ngan) OR (tai ngan)))) - hanh tang cua dung cong doan van ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet ngan) or (((thi ngan) OR (tai ngan)))) - hanh tang cua dung cong doan van ban*.