Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
ve thanh » le thanh, de thanh, den thanh
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
va cham » va chat, va tham
ve cham » ve chat, vu cham, ve chim
mang xa » lang xa, mang may, dang xay
xang xa » lang xa, ang xa, dang xay
cua tre » cua te, cuu tre, cua triet
cuu ve » cuu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty ((xang xa) OR (mang xa)) hoi. hieu ((ve cham) or (va cham)) cuu ve thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((xang xa) OR (mang xa)) hoi. hieu ((ve cham) OR (va cham)) cuu ve thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((xang xa) OR (mang xa)) hoi. hieu ((ve cham) or (va cham)) cuu ve thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((xang xa) OR (mang xa)) hoi. hieu ((ve cham) or (va cham)) cuu ve thanh dai cua tre*.