Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh hai » thanh phan, thanh hoa, thanh san
thuc ban » thuoc ban, thuc dan, thu ban
su triet » su viet, su tien, ve triet
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
ve nam » va nam, le nam, te nam
he nam » ha nam, nghe nam
hai su » hai vu, lai su, hai so
x hoi » xa hoi, o hoi, x ho

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: so sach ky nang x hoi. hieu ((ve nam) OR (he nam)) thuc ban thanh hai su triet~.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang x hoi. hieu ((ve nam) or (he nam)) thuc ban thanh hai su triet*.