Perhaps you should try some spelling variations:
thanh vinh » thanh tinh, than kinh, thanh van
thanh binh » thai binh, than kinh, tinh binh
va triet » va thiet, va trien, ve triet
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
nam xua » nam mua, nam qua, nam luat
ty nang » ky nang, ty xang, ty hang
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.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty nang o hoi. lieu va ((nam xua) or (nam cua)) va ((thanh vinh) OR (thanh binh)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang o hoi. lieu va ((nam xua) OR (nam cua)) va ((thanh vinh) OR (thanh binh)) va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang o hoi. lieu va ((nam xua) or (nam cua)) va ((thanh vinh) OR (thanh binh)) va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang o hoi. lieu va ((nam xua) or (nam cua)) va ((thanh vinh) OR (thanh binh)) va triet*.