Perhaps you should try some spelling variations:
hieu nghe » lieu nghe, hiem ngheo, nhiem nghe
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nano tu » nang tu, nano cau, nano cuo
dan lai » dan loai, dan lap, dan lat
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, me hoi
nao tu » tao tu, lao tu, cao tu
va dan » ca dan, va dao, va dau

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 nang ((ma hoi) or (ma hoa)). hieu nghe ((nano tu) OR (nao tu)) va dan lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((ma hoi) OR (ma hoa)). hieu nghe ((nano tu) OR (nao tu)) va dan lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((ma hoi) or (ma hoa)). hieu nghe ((nano tu) OR (nao tu)) va dan lai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((ma hoi) or (ma hoa)). hieu nghe ((nano tu) OR (nao tu)) va dan lai cua tre*.