Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
tu sach » thu sach, su sach, te sach
ky lang » ky nang, ky dang, ky tang
ky danh » ky anh, ky dang
hieu va » hieu qua
va hanh » van hanh, va thanh, va danh
vi cua » vai cua, di cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ky lang) or (ky danh)) xa hoi. ((hieu va) or (lieu va)) cac nuoc va hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky danh)) xa hoi. ((hieu va) OR (lieu va)) cac nuoc va hanh vi cua te.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) or (ky danh)) xa hoi. ((hieu va) or (lieu va)) cac nuoc va hanh vi cua te*.