Perhaps you should try some spelling variations:
thanh hoa » thanh pho
ban thanh » ban hanh, ban hang
sach ky » sach y, sach ty, sach kem
hoa cua » hoa chat, hoa xuat
bac can » ban can, bat can, tac can
bac cau » bach cau, ba cau, bac cao
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
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 ve ((bac cau) OR (bac can)) ban thanh hoa 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 ve ((bac cau) OR (bac can)) ban thanh hoa 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 ve ((bac cau) OR (bac can)) ban thanh hoa cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang xa hoi. hieu ve ((bac cau) OR (bac can)) ban thanh hoa cua tre*.