Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
thanh vai » thanh hai, thanh tai, thanh oai
toc sach » hoc sach, doc sach, thuoc sach
sach tu » sach thu, cach tu, sach ty
cuu tre » cua tre, cau tren, cau treo
xay hoi » tay hoi, cay phoi, gay thoi
hieu va » lieu va, hieu qua
toc va » hoc va, toc ta, tuc va
tu van » tu va
co toc » cao toc, co hoc, co doc
va co » vo co

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach tu van ((xay hoi) OR (xa hoi)). hieu va co toc va ((thanh vai) or (thanh van)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu van ((xay hoi) OR (xa hoi)). hieu va co toc va ((thanh vai) OR (thanh van)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tu van ((xay hoi) OR (xa hoi)). hieu va co toc va ((thanh vai) or (thanh van)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach tu van ((xay hoi) OR (xa hoi)). hieu va co toc va ((thanh vai) or (thanh van)) cuu tre*.