Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
vu sach » vu bach, su sach, vu khach
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
qua cac » cua cac
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
vi cua » di cua

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

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