Perhaps you should try some spelling variations:
sach kem » hanh kem
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
va hanh » va thanh, va danh, ban hanh
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 kem) or (sac ky)) nang xa hoi. hieu van cau truc ((va hanh) OR (van hanh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach kem) OR (sac ky)) nang xa hoi. hieu van cau truc ((va hanh) OR (van hanh)) dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach kem) or (sac ky)) nang xa hoi. hieu van cau truc ((va hanh) OR (van hanh)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach kem) or (sac ky)) nang xa hoi. hieu van cau truc ((va hanh) OR (van hanh)) dai cua tre*.