Perhaps you should try some spelling variations:
thang dai » hang dau, thanh hai, trung dai
cua triet » cua viet, su triet, va triet
truc van » truc va, thuc van, truc ban
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
hieu va » lieu va, hieu qua
tuc van » thuc van, tuc va, duc van

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 ky nang xa hoi. ((hieu ve) OR (hieu va)) cam ((tuc van) OR (truc van)) thang dai cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. ((hieu ve) or (hieu va)) cam ((tuc van) OR (truc van)) thang dai cua triet~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. ((hieu ve) or (hieu va)) cam ((tuc van) OR (truc van)) thang dai cua triet*.