Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cau thuc » cau truc, cuu thuc, can thuc
sach ky » sac ky, sach y, sach ty
van cau » van dau, van hau, van chat
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
dinh di » dinh du, dinh vi, danh di
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (cac ky)) nang x hoi. hieu van cau thuc va dinh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (cac ky)) nang x hoi. hieu van cau thuc va dinh di cua tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (cac ky)) nang x hoi. hieu van cau thuc va dinh di cua tre*.