Perhaps you should try some spelling variations:
thanh tu » hanh tu, nhanh tu, thanh tung
dang xay » dang van, van xay
so sach » so sanh, bo sach, co sach
xang xa » lang xa, mang xa, ang xa
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
loc va » hoc va
tu cua » hu cua, vu cua
ve cac » va cac, vien cac
luc va » duc va, tuc va
cua tu » cua tuc, cua su, cua cu

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 (dang xay)) hoi. hieu ve cac ((luc va) OR (loc va)) thanh tu cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((xang xa) OR (dang xay)) hoi. hieu ve cac ((luc va) OR (loc va)) thanh tu cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((xang xa) or (dang xay)) hoi. hieu ve cac ((luc va) OR (loc va)) thanh tu cua tu".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((xang xa) or (dang xay)) hoi. hieu ve cac ((luc va) OR (loc va)) thanh tu cua tu*.