Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hanh dai » hanh tai, hanh dao, vanh dai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
cau xuc » cam xuc, cau luc, cau truc
van cau » van dau, van hau, van chat
cua tre » cua te, cuu tre, cua triet
ky tang » ky nang, ky dang, kho tang
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thuoc sach)) ky tang ((van hoc) OR (van hoa)). hieu van cau xuc va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ky tang ((van hoc) OR (van hoa)). hieu van cau xuc va hanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuoc sach)) ky tang ((van hoc) OR (van hoa)). hieu van cau xuc va hanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) ky tang ((van hoc) OR (van hoa)). hieu van cau xuc va hanh dai cua tre*.