Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
dao thanh » ban thanh, tro thanh, de thanh
thuoc dao » thuoc bao, thuoc cao, thuoc dac
nam thuoc » nam thuc, nam thu, nha thuoc
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
toc sac » toc san, hoc sach, doc sach
doi cua » dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa

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

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