Perhaps you should try some spelling variations:
thanh dinh » thanh binh, thanh tinh, thanh vinh
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
qua nam » quan nam, cua nam, quang nam
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
su viet » so viet
co hoi » co hoc, co loi
o hoi » o hoc, o hai, o hoa

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 ty nang ((o hoi) OR (co hoi)). hieu qua nam xua gia thanh dinh ((su triet) OR (su viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((o hoi) OR (co hoi)). hieu qua nam xua gia thanh dinh ((su triet) or (su viet))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((o hoi) OR (co hoi)). hieu qua nam xua gia thanh dinh ((su triet) or (su viet))*.