Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
nang cau » nang cao, hang cau, nang dau
tai cua » thai cua, tai cuc, tri cua
cam luc » cam xuc, cau luc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach kem
hieu ve » hieu va
sach ty » sach y, sach tu, sach thu
luc va » duc va, tuc va, loc va

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

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