Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
ly nang » ky nang, ly hang, ly vang
van cac » van hac, van cau, van bac
y nang » ky nang, v nang, may nang
toc ta » toc tay, toc thai
vi cua » vai cua, di cua
cua cu » cua chu, cua cau, cua su
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: su sach ((y nang) OR (ly nang)) x hoi. hieu van cac ((toc ta) OR (hoc ma)) hanh vi cua cu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) OR (ly nang)) x hoi. hieu van cac ((toc ta) or (hoc ma)) hanh vi cua cu~".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) OR (ly nang)) x hoi. hieu van cac ((toc ta) or (hoc ma)) hanh vi cua cu*.