Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van chat » cao chat
dinh dai » dinh dat, dinh dao, dinh tai
sinh dai » sinh thai, si dai, sinh vat
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
xuc va » tuc va, luc va, xac va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang xa hoi. hieu van chat ((xuc va) OR (duc va)) ((dinh dai) or (sinh dai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. hieu van chat ((xuc va) OR (duc va)) ((dinh dai) OR (sinh dai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. hieu van chat ((xuc va) OR (duc va)) ((dinh dai) or (sinh dai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. hieu van chat ((xuc va) OR (duc va)) ((dinh dai) or (sinh dai)) cua tre*.