Perhaps you should try some spelling variations:
te sach » toc sach
co thuc » do thuc, co thua, mo thuc
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
tu nong » tu dong, tu cong, tu tong
tu nang » tru nang, tu nano, tu lang
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) OR (tu nong)) xa hoi. hieu va co thuc va hanh ((vai cua) or (lai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((tu nang) OR (tu nong)) xa hoi. hieu va co thuc va hanh ((vai cua) OR (lai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((tu nang) OR (tu nong)) xa hoi. hieu va co thuc va hanh ((vai cua) or (lai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((tu nang) OR (tu nong)) xa hoi. hieu va co thuc va hanh ((vai cua) or (lai cua)) tre*.