Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
chat xuc » chat huu, cam xuc, chao xu
van chat » cao chat
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
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: tu sach ky ((nang ma) OR (sang ma)) hoi. hieu van chat xuc ((va hanh) or (ban hanh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (sang ma)) hoi. hieu van chat xuc ((va hanh) OR (ban hanh)) dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang ma) OR (sang ma)) hoi. hieu van chat xuc ((va hanh) or (ban hanh)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) OR (sang ma)) hoi. hieu van chat xuc ((va hanh) or (ban hanh)) dai cua tre*.