Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cua triet » cua viet, su triet, va triet
hanh tai » thanh tai, han tai, hinh tai
hang tai » hang va, dung tai
truc va » thuc va, thuc vat, trung va
y nang » ky nang, ly nang, v nang
va cau » van cau, va cac, va dau
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

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: thuoc sach y nang ((x hoi) OR (o hoi)). lieu va cau truc va ((hanh tai) OR (hang tai)) cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach y nang ((x hoi) or (o hoi)). lieu va cau truc va ((hanh tai) OR (hang tai)) cua triet~".
• Adding a wildcard symbol may retrieve word variants: thuoc sach y nang ((x hoi) or (o hoi)). lieu va cau truc va ((hanh tai) OR (hang tai)) cua triet*.