Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh tai » thanh hai, thanh toan, doanh tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va giap » va giai, va gia, va giam
qua ban » cua ban, qua quan
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu
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 ky nang x hoi. hieu ((va giap) OR (va giup)) qua ban thanh tai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu ((va giap) OR (va giup)) qua ban thanh tai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu ((va giap) OR (va giup)) qua ban thanh tai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu ((va giap) OR (va giup)) qua ban thanh tai ((cua tre) or (cua te))*.