Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cau tren » cu tren, dau tren, ca tren
thanh vi » hanh vi, thanh va, thanh ve
dang xay » dang van, van xay
xay hoi » xa hoi, tay hoi, cay phoi
hieu ve » hieu va, hieu van
sach ty » sach tu, sach thu, xach tay
sac ky » cac ky, sai ky
ve nam » he nam, va nam, le nam
vi cau » va cau, ve cau, di cau

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 y) or (sach ty))) or (sac ky)) dang xay hoi. hieu ve nam cua ban thanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((((sach y) OR (sach ty))) OR (sac ky)) dang xay hoi. hieu ve nam cua ban thanh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: tu ((((sach y) or (sach ty))) or (sac ky)) dang xay hoi. hieu ve nam cua ban thanh vi cau tren*.