Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
van vanh » van hanh, van manh, van canh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
van anh » van thanh, tuan anh, van minh
cua tre » cua te, cuu tre, cua triet

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 nang xa hoi. hieu va cac nuoc ((van vanh) or (van anh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu va cac nuoc ((van vanh) OR (van anh)) dai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu va cac nuoc ((van vanh) or (van anh)) dai cua tre*.