Perhaps you should try some spelling variations:
ban thanh » ban hanh
ban hang » ngan hang
hang hai » hoang hai, hang tai, thanh hai
van nang » van quang, van ban, van dong
hai cua » thai cua, dai cua, hoi cua
va hang » van hang, va nang, va lang
so sach » so sanh, bo sach, co sach
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, voi nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((v nang) or (van nang)) mai hoi. hieu ((ban thanh) OR (ban hang)) duc va hang hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((v nang) OR (van nang)) mai hoi. hieu ((ban thanh) OR (ban hang)) duc va hang hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((v nang) or (van nang)) mai hoi. hieu ((ban thanh) OR (ban hang)) duc va hang hai cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ((v nang) or (van nang)) mai hoi. hieu ((ban thanh) OR (ban hang)) duc va hang hai cua tre*.