Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, va tinh, le thanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
van cau » van dau, van hau, van chat
cau tuc » cau truc, cau tu, cau luc
cua tre » cua te, cuu tre, dua tren

You may be able to get more results by adjusting your search query.

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