Perhaps you should try some spelling variations:
qua phap » quan phap, cua phap, qua phan
thanh di » thanh doi, thanh de, thanh do
sach thu » sach thue, sach thieu, sach tham
su sach » so sach, vu sach
lang ha » long ha
nang ma » tang ma, sang ma, nang cao
duy va » duy vat, duy van, duy v
di cua » dai cua, doi cua, de cua
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: su sach thu ((nang ma) OR (lang ha)) hoi. hieu qua phap ((duy va) OR (day va)) thanh di cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu ((nang ma) or (lang ha)) hoi. hieu qua phap ((duy va) OR (day va)) thanh di cua te~".
• Adding a wildcard symbol may retrieve word variants: su sach thu ((nang ma) or (lang ha)) hoi. hieu qua phap ((duy va) OR (day va)) thanh di cua te*.