Perhaps you should try some spelling variations:
duong cong » luong cong, duong trong, trong cong
hanh tran » hanh trang, thanh tran, hanh tram
dung cong » dung trong
ho trieu » mot trieu, 25 trieu, ho chieu
30 trieu » 25 trieu
tran van » luan van
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho trieu) OR (30 trieu)) tinh - hanh tran van ((duong cong) OR (dung cong)) dan toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho trieu) or (30 trieu)) tinh - hanh tran van ((duong cong) OR (dung cong)) dan toan cau~".
• Adding a wildcard symbol may retrieve word variants: ((ho trieu) or (30 trieu)) tinh - hanh tran van ((duong cong) OR (dung cong)) dan toan cau*.