Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dinh ve » dinh ket, dinh van
va dinh » van dinh, va kinh, va tinh
cam luc » cau luc
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
xang xa » lang xa, mang xa, ang xa
tu xang » ty xang, tu lang, tu quang
ve cuu » ve cau, ve chu, ve 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 xang xa hoi. hieu ve ((cam luc) or (cam xuc)) va dinh ve cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tu xang xa hoi. hieu ve ((cam luc) OR (cam xuc)) va dinh ve cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) tu xang xa hoi. hieu ve ((cam luc) or (cam xuc)) va dinh ve cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) tu xang xa hoi. hieu ve ((cam luc) or (cam xuc)) va dinh ve cuu tre*.