Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
cao thuc » cao thuoc, bao thuc, can thuc
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
cuu tre » cua tre, cau tren, cau treo
sach tu » cach tu, sach ty, sach uu
hieu va » lieu va
va cuu » va cau, va chu, va huu
x hoi » xa hoi, o hoi, x ho

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) or (sach thu)) nang x hoi. ((hieu va) OR (hieu qua)) cao thuc va hanh va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach tu) OR (sach thu)) nang x hoi. ((hieu va) OR (hieu qua)) cao thuc va hanh va cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach tu) or (sach thu)) nang x hoi. ((hieu va) OR (hieu qua)) cao thuc va hanh va cuu tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach tu) or (sach thu)) nang x hoi. ((hieu va) OR (hieu qua)) cao thuc va hanh va cuu tre*.