Perhaps you should try some spelling variations:
ban thanh » ban hang
giup qua » giap qua, giau qua, gioi qua
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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 ky nang x ho. hieu va giup qua ((ban thanh) OR (ban hanh)) vai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x ho. hieu va giup qua ((ban thanh) OR (ban hanh)) vai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x ho. hieu va giup qua ((ban thanh) OR (ban hanh)) vai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x ho. hieu va giup qua ((ban thanh) OR (ban hanh)) vai ((cua tre) or (cua te))*.