Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cac thuc » cach thuc, cac thu, can thuc
thuc day » thuc dan, thuc vat
day hang » dat hang, dai hang, day nang
hang dau » hang va, hang tai
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
hieu va » lieu va, hieu qua
dau cua » dai cua, day cua, cau cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang xa hoi. ((hieu ve) OR (hieu va)) cac thuc day hang dau cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang xa hoi. ((hieu ve) OR (hieu va)) cac thuc day hang dau cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang xa hoi. ((hieu ve) OR (hieu va)) cac thuc day hang dau cua tre*.