Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
gian cua » gian xu, ban cua
hieu van » hieu va, thien van, lieu va
lang ha » long ha
lang xa » dang xay, lang van
sach ky » sac ky, sach y, sach ty
van cau » van dau, van hau, van chat
toc va » hoc va, tuc va, loc va
toc ta » toc tay, toc thai
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: doc sach ky ((lang xa) OR (lang ha)) hoi. hieu van cau ((toc va) OR (toc ta)) dan gian cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ky ((lang xa) or (lang ha)) hoi. hieu van cau ((toc va) OR (toc ta)) dan gian cua te~".
• Adding a wildcard symbol may retrieve word variants: doc sach ky ((lang xa) or (lang ha)) hoi. hieu van cau ((toc va) OR (toc ta)) dan gian cua te*.