Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
chat xuc » chat huu, cam xuc, chao xu
hieu van » hieu va, thien van, lieu va
van chat » cao chat
sang tao » hang tai
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
nang ma » tang ma, sang ma, nang cao
hai cua » thai cua, dai cua, hoi cua
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: toc sach ky ((nang ma) or (sang tao)) hoa. hieu van chat xuc ((va hanh) or (ban hanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((nang ma) OR (sang tao)) hoa. hieu van chat xuc ((va hanh) OR (ban hanh)) hai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((nang ma) or (sang tao)) hoa. hieu van chat xuc ((va hanh) or (ban hanh)) hai cua tre*.