Perhaps you should try some spelling variations:
thuc day » thuc dan, thuc vat
day dinh » dao dinh, day danh, dang dinh
dinh vai » dinh van, dinh vi, dinh va
su triet » su viet, su tien, ve triet
va triet » va thiet, va trien, ve triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
o hoi » co hoi, o hoc, o hai
ve am » va am

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang ((x ho) or (o hoi)). hieu ve am thuc day dinh vai ((su triet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((x ho) OR (o hoi)). hieu ve am thuc day dinh vai ((su triet) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((x ho) or (o hoi)). hieu ve am thuc day dinh vai ((su triet) or (va triet))*.