Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
day thanh » dao thanh, dat thanh, da thanh
day hanh » day nhanh, dao hanh, day manh
te sach » toc sach
hoi cua » hoi chuc
ve tham » va tham, ve cham, vi tham
sach ly » sach y, sach lo, sach ty
hieu ve » hieu va, hieu van
mang xa » lang xa, mang may, dang xay
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: te sach ly ((mang xa) OR (nang x)) hoi. hieu ve tham thuc ((day hanh) OR (day thanh)) hoi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ly ((mang xa) or (nang x)) hoi. hieu ve tham thuc ((day hanh) OR (day thanh)) hoi cua tre~".
• Adding a wildcard symbol may retrieve word variants: te sach ly ((mang xa) or (nang x)) hoi. hieu ve tham thuc ((day hanh) OR (day thanh)) hoi cua tre*.