Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
sinh dai » sinh thai, si dai, sinh vat
dinh dai » dinh dat, dinh dao, dinh tai
chat xuc » chat huu, cam xuc, chao xu
van chat » cao chat
lang xa » lang ha, dang xay, lang van
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc 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 y ((nang ma) or (lang xa)) hoi. hieu van chat xuc va ((dinh dai) OR (sinh dai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((nang ma) OR (lang xa)) hoi. hieu van chat xuc va ((dinh dai) OR (sinh dai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y ((nang ma) or (lang xa)) hoi. hieu van chat xuc va ((dinh dai) OR (sinh dai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach y ((nang ma) or (lang xa)) hoi. hieu van chat xuc va ((dinh dai) OR (sinh dai)) cua tre*.