Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thanh lai » thanh hai, thanh lap, thanh loi
hieu van » thien van, lieu va, hieu ve
va thanh » gia thanh, ban thanh, va tinh
va triet » va thiet, va trien, ve triet
te sach » toc sach
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
lai va » loai va, mai va, dai va
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thuat sach) or (te sach)) ky nang x hoi. ((hieu van) OR (hieu va)) cac duc va thanh lai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuat sach) OR (te sach)) ky nang x hoi. ((hieu van) OR (hieu va)) cac duc va thanh lai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuat sach) or (te sach)) ky nang x hoi. ((hieu van) OR (hieu va)) cac duc va thanh lai va triet".
• Adding a wildcard symbol may retrieve word variants: ((thuat sach) or (te sach)) ky nang x hoi. ((hieu van) OR (hieu va)) cac duc va thanh lai va triet*.