Perhaps you should try some spelling variations:
cac nuoc » hoc nuoc, dat nuoc, cua nuoc
cap nuoc » dat nuoc
van hanh » van thanh, ban hanh, van anh
hanh dai » hanh tai, hanh dao, vanh dai
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky nang xa hoi. hieu va ((cac nuoc) OR (cap nuoc)) van hanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang xa hoi. hieu va ((cac nuoc) OR (cap nuoc)) van hanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang xa hoi. hieu va ((cac nuoc) OR (cap nuoc)) van hanh dai cua tre*.