Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
cua triet » cua viet, su triet, va triet
hieu van » thien van, lieu va, hieu ve
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
ca cua » co cua

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

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