Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
hanh tai » thanh tai, hang tai, han tai
nang xa » nang x, lang xa, nang ma
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky
xuc va » tuc va, luc va, xac va

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