Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
qua ban » qua quan
tai cuu » tai cuc, tai buu, tai cua
cuu tre » cua tre, cau tren, cau treo
me hoi » le hoi

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 ((me hoi) or (ma hoa)). hieu van nam ((qua ban) OR (cua ban)) thanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((me hoi) OR (ma hoa)). hieu van nam ((qua ban) OR (cua ban)) thanh tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((me hoi) or (ma hoa)). hieu van nam ((qua ban) OR (cua ban)) thanh tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((me hoi) or (ma hoa)). hieu van nam ((qua ban) OR (cua ban)) thanh tai cuu tre*.