Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
tai cua » thai cua, tai cuc, tri cua
van cau » van dau, van hau, van chat
lang xa » lang ha, dang xay, lang van
xac ky » cac ky, bac ky
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((xac ky) or (sac ky)) lang xa hoi. hieu van cau ((xuc va) OR (tuc va)) thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((xac ky) OR (sac ky)) lang xa hoi. hieu van cau ((xuc va) OR (tuc va)) thanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((xac ky) or (sac ky)) lang xa hoi. hieu van cau ((xuc va) OR (tuc va)) thanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((xac ky) or (sac ky)) lang xa hoi. hieu van cau ((xuc va) OR (tuc va)) thanh tai cua tre*.