Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, nam thu, nam tu
thanh de » hanh de, thanh ve, thanh do
lang van » dang van, hoang van, giang van
tang van » dang van, hoang van, trong van
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
de cua » le cua, te cua, dieu cua
cua te » cua tu

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 ty ((lang van) OR (tang van)) hoi. hieu va ((nam thuc) or (am thuc)) day thanh de cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty ((lang van) OR (tang van)) hoi. hieu va ((nam thuc) OR (am thuc)) day thanh de cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty ((lang van) OR (tang van)) hoi. hieu va ((nam thuc) or (am thuc)) day thanh de cua te*".