Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
van bao » van ban, van dao
duc van » duc va, duc manh, duc phan
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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 y nang x hoi. hieu van bao ((duc van) OR (duc tan)) thanh van ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu van bao ((duc van) OR (duc tan)) thanh van ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang x hoi. hieu van bao ((duc van) OR (duc tan)) thanh van ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu van bao ((duc van) OR (duc tan)) thanh van ((cua tre) or (cuu tre))*.