Perhaps you should try some spelling variations:
dang than » dang thanh, sang than, dang tran
than cua » nhan cua, thai cua, ban cua
thu sach » thuat sach, thuoc sach, thu hoach
van cac » van hac, van bac, dan cac
van cau » van dau, van hau, van chat
va dang » van dang, va nang, va lang
tu sach » su sach, te sach, tu cach
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (tu sach)) ky nang o hoi. thien ((van cac) OR (van cau)) nuoc va dang than cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ky nang o hoi. thien ((van cac) OR (van cau)) nuoc va dang than cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (tu sach)) ky nang o hoi. thien ((van cac) OR (van cau)) nuoc va dang than cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ky nang o hoi. thien ((van cac) OR (van cau)) nuoc va dang than cua tre*.