Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thu sach » thuat sach, thuoc sach, thu hoach
van tham » van tuan, van chat, van tai
cao hoc » co hoc, cho hoc, chat hoc
tu sach » su sach, te sach, tu cach
dan hai » doan hai, dang hai, dan khai
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
xuc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau

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)) y nang cao hoc. thi ((van tham) or (van thanh)) xuc va dan hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) y nang cao hoc. thi ((van tham) OR (van thanh)) xuc va dan hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (tu sach)) y nang cao hoc. thi ((van tham) or (van thanh)) xuc va dan hai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (tu sach)) y nang cao hoc. thi ((van tham) or (van thanh)) xuc va dan hai cua tre*.