Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van nang » van quang, van ban, van dong
tinh doi » trinh doc, trinh do, tinh hoc
doi cua » dai cua, hoi cua
va tinh » may tinh
cam tuc » cam xuc, nam thuc, dam thuc
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
su dang » su dung
cam tu » cam thu, nam tu, dam tu

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 ((van nang) OR (su dang)) xa hoi. hieu va ((cam tuc) OR (cam tu)) va tinh doi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((van nang) or (su dang)) xa hoi. hieu va ((cam tuc) OR (cam tu)) va tinh doi cua tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach ((van nang) or (su dang)) xa hoi. hieu va ((cam tuc) OR (cam tu)) va tinh doi cua tre*.