Perhaps you should try some spelling variations:
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
nang xa » lang xa, nang ma, mang xa
hieu va » lieu va, hieu qua
co thuc » do thuc, co thua, mo thuc
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tri cua, dai cua
va co » vo co

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach tu ((nang xa) or (nang x)) hoi. hieu va co thuc va hanh ((tai cua) OR (tai cuc)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu ((nang xa) OR (nang x)) hoi. hieu va co thuc va hanh ((tai cua) OR (tai cuc)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach tu ((nang xa) or (nang x)) hoi. hieu va co thuc va hanh ((tai cua) OR (tai cuc)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach tu ((nang xa) or (nang x)) hoi. hieu va co thuc va hanh ((tai cua) OR (tai cuc)) tre*.