Perhaps you should try some spelling variations:
thanh lap » thanh san, phan lap, thanh hai
cua triet » cua viet, su triet, va triet
hieu van » thien van, lieu va, hieu ve
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
hau duc » huu duc, ha duc, pham duc
lap cua » lai cua, tap cua, lam cua
co hoi » co hoc, co loi
o hoi » o hoc, o hai, o hoa

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