Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
tam thuc » tham thuc, am thuc, nam thuc
thuc day » thuc dan, thuc vat
thanh va » thanh van, hanh va, thanh ha
cua tre » cua te, cua triet, dua tren
tu sach » thu sach, su sach, te sach
cao hoi » cau hoi, cao hoc, tao hoi
hieu va » lieu va, hieu qua
cuu tre » cau tren, cau treo
va tam » van tam, va tham, va tac
y nang » ky nang, ly nang, v nang
co hoi » co hoc, co loi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang ((cao hoi) or (co hoi)). hieu va tam thuc day thanh va ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((cao hoi) OR (co hoi)). hieu va tam thuc day thanh va ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((cao hoi) or (co hoi)). hieu va tam thuc day thanh va ((cua tre) or (cuu tre))*.