Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh vi » hanh vi, thanh va, thanh ve
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
qua cac » cua cac
cua tre » cuu tre, cua triet, dua tren
du van » duy van, duc van, tu van
cua te » cua tu

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty xang xa hoi. hieu qua cac du van thanh vi ((cua tre) OR (cua te))~.
• Adding a wildcard symbol may retrieve word variants: so sach ty xang xa hoi. hieu qua cac du van thanh vi ((cua tre) or (cua te))*.