Perhaps you should try some spelling variations:
thanh trinh » hanh trinh, thanh tinh, thanh binh
su triet » su tien, ve triet
tu sach » thu sach, su sach, te sach
nam xua » nam cua, nam mua, nam qua
xua gia » cua gia, qua gia, xua kia
hieu va » lieu va
su viet » so viet
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
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: tu sach y nang o hoi. ((hieu va) OR (hieu qua)) nam xua gia thanh trinh ((su triet) OR (su viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang o hoi. ((hieu va) or (hieu qua)) nam xua gia thanh trinh ((su triet) OR (su viet))~".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang o hoi. ((hieu va) or (hieu qua)) nam xua gia thanh trinh ((su triet) OR (su viet))*.