Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van nhan » van phan, van thanh, danh nhan
nhan luc » nang luc
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
van anh » van thanh, van minh
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu
tuan » quan, tran, luan

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

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xa hoi. hieu van nhan luc ((van anh) OR (tuan anh)) ve ((cua tre) OR (cua te))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xa hoi. hieu van nhan luc ((van anh) or (tuan anh)) ve ((cua tre) OR (cua te))~".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xa hoi. hieu van nhan luc ((van anh) or (tuan anh)) ve ((cua tre) OR (cua te))*.