Perhaps you should try some spelling variations:
thanh vinh » thanh binh, thanh tinh, thanh van
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
cua va » cua vat, chua va, cua van
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) OR (ty hang)) o hoi. hieu va nam cua va ((thanh vinh) or (than kinh)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty hang)) o hoi. hieu va nam cua va ((thanh vinh) OR (than kinh)) va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ty hang)) o hoi. hieu va nam cua va ((thanh vinh) or (than kinh)) va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ty hang)) o hoi. hieu va nam cua va ((thanh vinh) or (than kinh)) va triet*.