Perhaps you should try some spelling variations:
ban thanh » ban hang
hoc tach » hoc sach, hoc cach, hoc tich
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
van hoc » van hoa
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
tu sach » thu sach, su sach, te sach
dai ve » dap ve, dai va, dai de
dau ve » dap ve
x hoi » xa hoi, o hoi, x ho

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 x hoi. hieu van hoc tach ((ban thanh) or (ban hanh)) ((dai ve) OR (dau ve)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. hieu van hoc tach ((ban thanh) OR (ban hanh)) ((dai ve) OR (dau ve)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. hieu van hoc tach ((ban thanh) or (ban hanh)) ((dai ve) OR (dau ve)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. hieu van hoc tach ((ban thanh) or (ban hanh)) ((dai ve) OR (dau ve)) triet*.