Perhaps you should try some spelling variations:
thanh gian » thanh giang, thach giang, thanh san
ve triet » va trien, su triet
thanh gi » thanh nghi, thanh hai, thanh ngu
cap nuoc » dat nuoc
tu sach » thu sach, su sach, te sach
ly hang » ly quang
ty hang » ty xang, thi hang, thu hang
hieu ve » hieu va, hieu van
ve cap » ve cac, le cap, ve cai
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: tu sach ((ty hang) or (ly hang)) o hoi. hieu ve cap nuoc va ((thanh gi) OR (thanh gian)) ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty hang) OR (ly hang)) o hoi. hieu ve cap nuoc va ((thanh gi) OR (thanh gian)) ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty hang) or (ly hang)) o hoi. hieu ve cap nuoc va ((thanh gi) OR (thanh gian)) ve triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty hang) or (ly hang)) o hoi. hieu ve cap nuoc va ((thanh gi) OR (thanh gian)) ve triet*.