Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
nam thuc » am thuc, nam thu, nam tu
hanh vai » hanh vi, hanh va, hanh tai
hieu van » thien van, lieu va, hieu ve
day hanh » day nhanh, day thanh, dao hanh
te sach » toc sach
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
danh ma » anh ma, danh ca, hanh ma
ky danh » ky anh, ky dang

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky danh ma hoa. ((hieu van) or (hieu va)) ((nam thuc) OR (nam thuoc)) day hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky danh ma hoa. ((hieu van) OR (hieu va)) ((nam thuc) OR (nam thuoc)) day hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky danh ma hoa. ((hieu van) or (hieu va)) ((nam thuc) OR (nam thuoc)) day hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky danh ma hoa. ((hieu van) or (hieu va)) ((nam thuc) OR (nam thuoc)) day hanh vai cua tre*.