Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cau thuc » cau truc, cuu thuc, can thuc
vat hanh » vat thanh, van hanh, va hanh
sach ty » sach tu, sach thu, xach tay
cao cho » cap cho, cao chat
van cau » van dau, van hau, van chat
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) or (sach y)) nang cao cho. hieu van cau thuc vat hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach y)) nang cao cho. hieu van cau thuc vat hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sach y)) nang cao cho. hieu van cau thuc vat hanh di cua tre*.