Perhaps you should try some spelling variations:
lang hoi » lang hai, quang hoi, lang chai
cua tre » cua te, cuu tre, cua triet
hoi cua » hoi chuc
va lang » va nang, hoa lang
luc va » duc va, tuc va, loc va
tu bai » tu ban, tu bat, te bai
bai ky » ban ky, sai ky, bac ky
va cao » va cac, va co, va dao
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu bai ky nang ((o hoi) OR (o hai)). hieu ((va cao) or (ca dao)) luc va lang hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu bai ky nang ((o hoi) OR (o hai)). hieu ((va cao) OR (ca dao)) luc va lang hoi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu bai ky nang ((o hoi) OR (o hai)). hieu ((va cao) or (ca dao)) luc va lang hoi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu bai ky nang ((o hoi) OR (o hai)). hieu ((va cao) or (ca dao)) luc va lang hoi cua tre*.