Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
thuc dan » thuc hanh, thuc vat
cua tre » cua te, cuu tre, cua triet
tu sac » tu sach, tu cac, tu san
tu ban » thu ban, te ban
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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