Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
va triet » va thiet, va trien, ve triet
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
van nham » van nam, van nhan, van tham
doc sach » hoc sach, toc sach, nuoc sach
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
vai va » mai va, dai va, hai va
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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) OR (doc sach)) ky nang ((x hoi) OR (o hoi)). hieu van nham thuc va hanh vai va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (doc sach)) ky nang ((x hoi) OR (o hoi)). hieu van nham thuc va hanh vai va triet~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (doc sach)) ky nang ((x hoi) OR (o hoi)). hieu van nham thuc va hanh vai va triet*.