Perhaps you should try some spelling variations:
vi triet » ve triet, va triet, tim triet
duoc hoi » quoc hoi, duoc hoc, duc hoa
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
cao tuc » dao tuc, cao duc, cao suc
vu sach » vu bach, vu khach
su sach » so sach
va cao » va cac, va co, va dao
tuc va » thuc va, truc va, tuc xa
va vi » ba vi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (su sach)) van ban ((duoc hoi) OR (duoc si)). lieu va cao tuc va danh va vi triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (su sach)) van ban ((duoc hoi) OR (duoc si)). lieu va cao tuc va danh va vi triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (su sach)) van ban ((duoc hoi) OR (duoc si)). lieu va cao tuc va danh va vi triet".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (su sach)) van ban ((duoc hoi) OR (duoc si)). lieu va cao tuc va danh va vi triet*.