Perhaps you should try some spelling variations:
van quang » van quan, tran quang, van tuan
ban hanh » ban hang
su bach » vu bach, su sach, huu bach
hieu ve » hieu va, hieu van
cac xuc » cam xuc, cac nuoc, chat xuc
xuc ban » duc ban, cuc ban, quoc ban
ve cac » va cac, vien cac
vi su » ve su, ki su, oi su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su bach ((van quang) or (van ban)) xa hoi. hieu ve cac xuc ban hanh ((vi su) OR (va su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su bach ((van quang) OR (van ban)) xa hoi. hieu ve cac xuc ban hanh ((vi su) OR (va su)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su bach ((van quang) or (van ban)) xa hoi. hieu ve cac xuc ban hanh ((vi su) OR (va su)) triet".
• Adding a wildcard symbol may retrieve word variants: su bach ((van quang) or (van ban)) xa hoi. hieu ve cac xuc ban hanh ((vi su) OR (va su)) triet*.