Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
tham duc » pham duc, tham du, than duc
ban hanh » ban hang
mai hoi » mai khoi, dai hoi, lai hoi
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
san ky » sang ky, dan ky, ban ky
me hoi » le hoi
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((san ky) OR (van ky)) nang ((me hoi) or (mai hoi)). hieu van tham duc ban hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((san ky) OR (van ky)) nang ((me hoi) OR (mai hoi)). hieu van tham duc ban hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((san ky) OR (van ky)) nang ((me hoi) or (mai hoi)). hieu van tham duc ban hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((san ky) OR (van ky)) nang ((me hoi) or (mai hoi)). hieu van tham duc ban hanh vi cua tre*.