Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » hieu va, thien van, lieu va
dinh dat » dinh ket, dinh van, dinh lam
dinh dai » sinh dai, dinh dao, dinh tai
chat huu » pham huu
van chat » cao chat
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
huu va » cuu va, tuu va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky ((nang ma) or (nang x)) hoi. hieu van chat huu va ((dinh dai) or (dinh dat)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky ((nang ma) OR (nang x)) hoi. hieu van chat huu va ((dinh dai) OR (dinh dat)) cua tre.
• Adding a wildcard symbol may retrieve word variants: thuat sach ky ((nang ma) or (nang x)) hoi. hieu van chat huu va ((dinh dai) or (dinh dat)) cua tre*.