Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hang doi » hang loi, huong doi, hang tai
su sach » so sach, vu sach
co sach » bo sach, cuon sach, hoc sach
hieu va » lieu va, hieu qua
cac toc » cac toi, cac nuoc, cac thoi
hang di » hang vi, hang dien, hang dich
toc va » hoc va, toc ta, tuc va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (co sach)) ky nang x ho. hieu va cac toc va ((hang di) OR (hang doi)) cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (co sach)) ky nang x ho. hieu va cac toc va ((hang di) OR (hang doi)) cua triet~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (co sach)) ky nang x ho. hieu va cac toc va ((hang di) OR (hang doi)) cua triet*.