Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
hanh tai » thanh tai, hang tai, han tai
hanh vai » hanh vi, hanh va, hanh van
lang van » dang van, tang van, hoang van
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
sach ty » sach y, sach thu, xach tay
van hoi » van hoa, van hoc, van hoe
sach tu » sach thu, cach tu, sach uu
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 ((sach ty) or (sach tu)) lang van hoi. hieu vu cham thuc vat ((hanh vai) or (hanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach tu)) lang van hoi. hieu vu cham thuc vat ((hanh vai) OR (hanh tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach tu)) lang van hoi. hieu vu cham thuc vat ((hanh vai) or (hanh tai)) cua tre*.