Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
dua ban » dia ban, cua ban, qua ban
cua tre » cua te, cuu tre, cua triet
ky dang » ky nang, ky danh
ky sang » ky nang, ky tang, duy sang
ca dua » cay dua, ca cua, ca da
van ca » van cau, van cua, dan ca

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 sang) OR (ky dang)) ma hoa. hieu van ca dua ban ((thanh hai) OR (thanh san)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky sang) OR (ky dang)) ma hoa. hieu van ca dua ban ((thanh hai) or (thanh san)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky sang) OR (ky dang)) ma hoa. hieu van ca dua ban ((thanh hai) or (thanh san)) cua tre*.