Perhaps you should try some spelling variations:
sach danh » sach tranh, sach dung, sach kinh
danh tren » doanh tren, dinh tren, dan tren
sach ran » sach han, sach san, sach tranh
ran tren » tran tren, van tren, dan tren
sach dao » lanh dao
so sach » so sanh, bo sach, co sach
sach xa » sach nha, sach bai

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: (((( so sach danh tren ) OR ( so sach ran tren ))) OR ( vu ((sach xa) OR (sach dao)) tren ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( so sach danh tren ) or ( so sach ran tren ))) or ( vu ((sach xa) OR (sach dao)) tren ))~".
• Adding a wildcard symbol may retrieve word variants: (((( so sach danh tren ) or ( so sach ran tren ))) or ( vu ((sach xa) OR (sach dao)) tren ))*.