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