Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
dang xay » dang van, van xay
va thanh » gia thanh, va tinh, le thanh
hieu van » hieu va, thien van, lieu va
cac tuc » cac toc, cac tu, cac tac
van cac » van hac, van cau, van bac
sach ky » sac ky, sach ty, sach kem
xay hoi » xa hoi, tay hoi, cay phoi
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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 ky) OR (sach y)) dang xay hoi. hieu van cac tuc ((va thanh) or (ban thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach ky) OR (sach y)) dang xay hoi. hieu van cac tuc ((va thanh) OR (ban thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sach ky) OR (sach y)) dang xay hoi. hieu van cac tuc ((va thanh) or (ban thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu ((sach ky) OR (sach y)) dang xay hoi. hieu van cac tuc ((va thanh) or (ban thanh)) vi cua tre*.