Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van dinh » van minh, van dich, va dinh
tu quang » vu quang, chu quang, bui quang
quang xa » quan xa, quang ma, quang va
cau luc » cau truc, cau phuc
dinh ve » dinh ket, dinh van
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
ve cua » le cua, de cua, te cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) tu quang xa hoi. hieu ve ((cau luc) or (cam xuc)) van dinh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tu quang xa hoi. hieu ve ((cau luc) OR (cam xuc)) van dinh ve cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) tu quang xa hoi. hieu ve ((cau luc) or (cam xuc)) van dinh ve cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) tu quang xa hoi. hieu ve ((cau luc) or (cam xuc)) van dinh ve cua tre*.