Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
duc ban » duc tan, duc van, duc man
dua ban » cua ban, qua ban, mua ban
su viet » so viet
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
x hoi » xa hoi, o hoi, x ho
vi su » va su, ve su, ki su

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: tu sach v nang x hoi. hieu va cac ((((duc ban) OR (dua ban))) OR (dia ban)) hanh vi su viet~.
• Adding a wildcard symbol may retrieve word variants: tu sach v nang x hoi. hieu va cac ((((duc ban) or (dua ban))) or (dia ban)) hanh vi su viet*.