Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
thanh doi » thanh loi, thanh moi, thanh do
hieu van » hieu va, thien van, lieu va
thuoc da » thuoc dac, thuoc ma, thuoc va
da thanh » dao thanh, dat thanh, dam thanh
sach ky » sac ky, sach kem, sach hay
sach ty » sach tu, sach thu, xach tay
lang xa » lang ha, dang xay, lang van
doi 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.

• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((((sach ky) OR (sach ty))) OR (sach y)) lang xa hoi. hieu van nam thuoc da thanh doi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((((sach ky) OR (sach ty))) or (sach y)) lang xa hoi. hieu van nam thuoc da thanh doi cua tre~".
• Adding a wildcard symbol may retrieve word variants: toc ((((sach ky) OR (sach ty))) or (sach y)) lang xa hoi. hieu van nam thuoc da thanh doi cua tre*.