Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
tang van » dang van, hoang van, trong van
thuc day » thuc dan, thuc vat
tu cach » tu cac
tu sach » thu sach, su sach, te sach
ky tang » ky nang, ky dang, kho tang
van hoi » van hoa, van hoc, van hoe
hieu va » lieu va, hieu qua
va cham » va chat, va tham
day dan » day danh, dao dan, cay dan
dan dai » dat dai, can dai, dan dat
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (tu sach)) ky tang van hoi. hieu va cham thuc day dan dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (tu sach)) ky tang van hoi. hieu va cham thuc day dan dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (tu sach)) ky tang van hoi. hieu va cham thuc day dan dai cua tre*.