Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
cuu tre » cau tren, cau treo
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
va cham » va chat, va tham
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
cua tre » cua te, cua triet, dua tren

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 tu ((nang xa) OR (lang xa)) hoi. hieu va cham thuc va hanh di ((cuu tre) OR (cua tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach tu ((nang xa) or (lang xa)) hoi. hieu va cham thuc va hanh di ((cuu tre) OR (cua tre))~".
• Adding a wildcard symbol may retrieve word variants: te sach tu ((nang xa) or (lang xa)) hoi. hieu va cham thuc va hanh di ((cuu tre) OR (cua tre))*.