Perhaps you should try some spelling variations:
thien van » thi van
ban thanh » ban hanh, ban hang
thanh dai » thanh hai, thanh tai, thanh dat
cua triet » cua viet, su triet, va triet
hieu van » hieu va, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
cac dai » cac dan, cac bai, can dai
dai ban » dai han, tai ban, di ban
y nang » ky nang, ly nang, v nang
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.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang ((x hoi) or (o hoi)). ((hieu van) or (thien van)) cac dai ban thanh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((x hoi) OR (o hoi)). ((hieu van) OR (thien van)) cac dai ban thanh dai cua triet.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((x hoi) or (o hoi)). ((hieu van) or (thien van)) cac dai ban thanh dai cua triet*.