Perhaps you should try some spelling variations:
sieu viet » su viet, dien viet, bien viet
thanh dat » thanh san, thanh hai, thanh van
sach kho » bach khoa, sach dao, sach nha
kho tang » cao tang
hanh dao » lanh dao, thanh dam, doanh dao
tu sach » thu sach, su sach, te sach
cao luc » bao luc, cao duc, cao suc
hieu va » lieu va, hieu qua
luc va » duc va, tuc va, loc va
ma hoi » mai hoi, ma hoa, me hoi
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach kho tang ((ma hoi) OR (xa hoi)). hieu va cao luc va ((hanh dao) or (thanh dat)) sieu viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach kho tang ((ma hoi) OR (xa hoi)). hieu va cao luc va ((hanh dao) OR (thanh dat)) sieu viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach kho tang ((ma hoi) OR (xa hoi)). hieu va cao luc va ((hanh dao) or (thanh dat)) sieu viet".
• Adding a wildcard symbol may retrieve word variants: tu sach kho tang ((ma hoi) OR (xa hoi)). hieu va cao luc va ((hanh dao) or (thanh dat)) sieu viet*.