Perhaps you should try some spelling variations:
thieu nien » thien nhien
nien cac » vien cac, dien cac, bien cac
cac giai » tac gia, cuu giai, hoc giai
lang hai » lang chai, lang thai, lang ha
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
giai va » giai van, gia va, giai ma
va lang » va nang, hoa lang
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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 hoi. thieu nien cac giai va lang hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang ma hoi. thieu nien cac giai va lang hai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang ma hoi. thieu nien cac giai va lang hai cua tre*.