Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
truc van » truc va, thuc van, truc ban
co sach » bo sach, cuon sach, hoc sach
ky dang » ky nang
ky danh » ky anh
qua hai » qua hoat
tuc van » thuc van, tuc va, duc van
vi cua » vai cua, di cua

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: co sach ((ky dang) OR (ky danh)) xa hoi. hieu qua hai ((tuc van) OR (truc van)) hanh vi cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ((ky dang) OR (ky danh)) xa hoi. hieu qua hai ((tuc van) or (truc van)) hanh vi cua triet~".
• Adding a wildcard symbol may retrieve word variants: co sach ((ky dang) OR (ky danh)) xa hoi. hieu qua hai ((tuc van) or (truc van)) hanh vi cua triet*.