Perhaps you should try some spelling variations:
tang thanh » dang thanh, trung thanh, hoang thanh
thanh tai » thanh hai, thanh toan, doanh tai
duc tang » duc thang, duc tan, tuc tang
hieu van » thien van, lieu va, hieu ve
tu sach » thu sach, su sach, tu cach
bao duc » dao duc, bao luc, cao duc
tai cuu » tai cuc, tai buu, tai cua
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
te sach » toc sach
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) or (te sach)) y nang x hoi. ((hieu van) OR (hieu va)) bao duc tang thanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) y nang x hoi. ((hieu van) OR (hieu va)) bao duc tang thanh tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) y nang x hoi. ((hieu van) OR (hieu va)) bao duc tang thanh tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) y nang x hoi. ((hieu van) OR (hieu va)) bao duc tang thanh tai cuu tre*.