Perhaps you should try some spelling variations:
hieu nghe » lieu nghe, hiem ngheo, nhiem nghe
danh dai » danh dau, danh di, danh sai
xac danh » xac dinh, tac danh, sach danh
nghe nam » nghe lam, nghiep nam, nghe nano
tu sach » thu sach, te sach, tu cach
thu xac » thau xay
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet

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