Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
lam duoc » nam duoc, luat duoc, lam thuoc
va thanh » gia thanh, va tinh, le thanh
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
van lam » van nam
cua tre » cua te, cuu tre, cua triet
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: tu ((sach ky) or (sac ky)) nang xa hoi. hieu van lam duoc ((va thanh) OR (ban thanh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang xa hoi. hieu van lam duoc ((va thanh) OR (ban thanh)) dai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) nang xa hoi. hieu van lam duoc ((va thanh) OR (ban thanh)) dai cua tre*".