Perhaps you should try some spelling variations:
trung thanh » truong thanh
duc trung » dac trung, dung trung, do trung
thanh lai » thanh hai, thanh lap, thanh loi
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cua tre » cuu tre, cua triet, dua tren
van bao » van ban, van dao
bao duc » dao duc, bao luc, cao duc
te sach » toc sach
y nang » ky nang, ly nang, v nang
cua te » cua tu
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: ((thu sach) or (te sach)) y nang x hoi. hieu van bao duc trung thanh lai ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (te sach)) y nang x hoi. hieu van bao duc trung thanh lai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (te sach)) y nang x hoi. hieu van bao duc trung thanh lai ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (te sach)) y nang x hoi. hieu van bao duc trung thanh lai ((cua tre) OR (cua te))*.