Perhaps you should try some spelling variations:
thanh nha » thanh nhan, thanh ha, thanh nga
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam tu
da thanh » dao thanh, dat thanh, dam thanh
sach ty » sach tu, sach thu, xach tay
nha cua » nhat cua, nhan cua, nghia cua
cua tre » cua te, cuu tre, cua triet
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: vu ((sach ty) OR (sach y)) nang x hoi. hieu van ((nam thuc) or (nam thu)) da thanh nha cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach ty) OR (sach y)) nang x hoi. hieu van ((nam thuc) OR (nam thu)) da thanh nha cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sach ty) OR (sach y)) nang x hoi. hieu van ((nam thuc) or (nam thu)) da thanh nha cua tre*".