Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
chat soc » cham soc, chat hoc, chat doc
danh dai » danh dau, danh di, vanh dai
danh sai » dung sai, danh bat, danh dau
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
soc va » hoc va, loc va, doc va

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 ky nang xa hoi. ((hieu van) OR (lieu va)) chat soc va ((danh dai) or (danh sai)) cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. ((hieu van) OR (lieu va)) chat soc va ((danh dai) OR (danh sai)) cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. ((hieu van) OR (lieu va)) chat soc va ((danh dai) or (danh sai)) cua vat".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. ((hieu van) OR (lieu va)) chat soc va ((danh dai) or (danh sai)) cua vat*.