Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
va thanh » gia thanh, va tinh, le thanh
vu sach » vu bach, su sach, vu khach
cam thu » nam thu, cac thu, ca thu
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
lang xa » lang ha, dang xay, lang van
va cua » va chua, via cua, ca cua
ve cam » ve cham, ve cac, va cam

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 y ((lang xa) or (tang ma)) hoi. hieu ve cam thu ((va thanh) OR (ban thanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y ((lang xa) OR (tang ma)) hoi. hieu ve cam thu ((va thanh) OR (ban thanh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach y ((lang xa) or (tang ma)) hoi. hieu ve cam thu ((va thanh) OR (ban thanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach y ((lang xa) or (tang ma)) hoi. hieu ve cam thu ((va thanh) OR (ban thanh)) va cua tre*.