Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
hieu van » hieu va, thien van, lieu va
thu sai » thu hai, thu tai, thu san
dua ban » dia ban, qua ban, mua ban
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
sai ky » sac ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sai ky nang ((xa hoi) or (ma hoa)). hieu van nam ((dua ban) OR (cua ban)) thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sai ky nang ((xa hoi) OR (ma hoa)). hieu van nam ((dua ban) OR (cua ban)) thanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sai ky nang ((xa hoi) or (ma hoa)). hieu van nam ((dua ban) OR (cua ban)) thanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sai ky nang ((xa hoi) or (ma hoa)). hieu van nam ((dua ban) OR (cua ban)) thanh vai cua tre*.