Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
van hanh » van thanh, ban hanh, van anh
xang xa » lang xa, mang xa, ang xa
hieu va » lieu va, hieu qua
cam tuc » cam tu, nam thuc, dam thuc
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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) OR (doc sach)) ty xang xa hoi. hieu va ((cam tuc) OR (cam xuc)) van hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ty xang xa hoi. hieu va ((cam tuc) or (cam xuc)) van hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ty xang xa hoi. hieu va ((cam tuc) or (cam xuc)) van hanh vi cua tre*.