Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
ve triet » va trien, su triet
su sach » so sach, vu sach
ly nang » ky nang, ly hang, ly vang
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
y nang » ky nang, v nang, may nang
ve cac » va cac, vien cac
ca ve » ca va, va ve

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