Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
van cam » van nam, van lam, van cau
lam cua » nam cua, lam chat
so hoc » co hoc, mo hoc, so hoa
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: vu sach ky nang ((o hoi) or (so hoc)). hieu van cam xuc ((gia thanh) or (ban thanh)) lam cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang ((o hoi) OR (so hoc)). hieu van cam xuc ((gia thanh) OR (ban thanh)) lam cua triet.
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang ((o hoi) or (so hoc)). hieu van cam xuc ((gia thanh) or (ban thanh)) lam cua triet*.