Perhaps you should try some spelling variations:
dinh vai » dinh van, dinh vi, dinh tai
dang xay » dang van, van xay
dinh va » dinh van, dinh ve, tinh va
cac lop » cac hop, cac loai
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
xay hoi » xa hoi, tay hoi, cay phoi
cuu tre » cua tre, cau tren, cau treo
ve cac » va cac, vien cac
lop va » lap va, hop va, nop va
sac ky » cac ky, sai ky

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 ky) or (sac ky)) dang xay hoi. hieu ve cac lop va ((dinh vai) or (dinh va)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) dang xay hoi. hieu ve cac lop va ((dinh vai) OR (dinh va)) cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) dang xay hoi. hieu ve cac lop va ((dinh vai) or (dinh va)) cuu tre*.