Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » thien van, lieu va, hieu ve
cac thuc » cach thuc, cac thu, can thuc
thuc ban » thuoc ban, thuc dan, thu ban
ban dinh » ban tinh, van dinh, ban dich
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
dinh du » dinh duc, dinh cu, dinh tu
du cua » duy cua, dau cua, dum cua
x hoi » o hoi, x ho, 5 hoi

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 ((x hoi) or (xa hoi)). ((hieu van) OR (hieu va)) cac thuc ban dinh du cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (xa hoi)). ((hieu van) OR (hieu va)) cac thuc ban dinh du cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) or (xa hoi)). ((hieu van) OR (hieu va)) cac thuc ban dinh du cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (xa hoi)). ((hieu van) OR (hieu va)) cac thuc ban dinh du cua triet*.