Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cua triet » cua viet, su triet, va triet
day thanh » dao thanh, dat thanh, da thanh
thuc day » thuc dan, thuc vat
thanh vi » hanh vi, thanh va, thanh ve
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ve tham » va tham, ve cham, vi tham
hieu ve » hieu va, hieu van
cao hoi » cau hoi, cao hoc, tao hoi
cuu tre » cua tre, cau tren, cau treo
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 ky nang ((cao hoi) or (co hoi)). hieu ve tham thuc day thanh vi ((cua triet) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((cao hoi) OR (co hoi)). hieu ve tham thuc day thanh vi ((cua triet) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((cao hoi) or (co hoi)). hieu ve tham thuc day thanh vi ((cua triet) or (cuu tre))*.