Perhaps you should try some spelling variations:
sach vay » sach va, sach hay, sach nay
ban hanh » ban hang
quoc ban » quoc bao, quoc lan, quoc quan
hanh ve » hanh vi, hanh va, hanh kem
su tien » su kien, su hien, tu tieng
ve cam » ve cham, va cam, ve cai
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho
ve su » va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach vay) or (sach y)) nang x hoi. hieu ((ve cam) or (ve cac)) quoc ban hanh ve su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach vay) OR (sach y)) nang x hoi. hieu ((ve cam) OR (ve cac)) quoc ban hanh ve su tien.
• Adding a wildcard symbol may retrieve word variants: tu ((sach vay) or (sach y)) nang x hoi. hieu ((ve cam) or (ve cac)) quoc ban hanh ve su tien*.