Perhaps you should try some spelling variations:
nam xuc » cam xuc, nam xua, nam thuc
hanh di » hanh de, hang di, danh di
cua tre » cua te, cuu tre, cua triet
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
va nam » van nam, ha nam, va nay
xuc va » duc va, tuc va, luc va
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky nang ((o hoi) or (xa hoi)). lieu va nam xuc va ((hanh di) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang ((o hoi) OR (xa hoi)). lieu va nam xuc va ((hanh di) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang ((o hoi) or (xa hoi)). lieu va nam xuc va ((hanh di) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang ((o hoi) or (xa hoi)). lieu va nam xuc va ((hanh di) OR (hanh vi)) cua tre*.