Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
nam tu » nam thu, nam thuc
di cua » dai cua, doi cua, de cua
x hoi » o hoi, x ho, 5 hoi

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 ((x hoi) OR (xa hoi)). hieu van ((nam thuoc) or (nam tu)) van hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((x hoi) OR (xa hoi)). hieu van ((nam thuoc) OR (nam tu)) van hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang ((x hoi) OR (xa hoi)). hieu van ((nam thuoc) or (nam tu)) van hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((x hoi) OR (xa hoi)). hieu van ((nam thuoc) or (nam tu)) van hanh di cua tre*.