Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
hanh di » hanh de, hang di, danh di
cam luc » cam xuc, cau luc
cuu tre » cua tre, cau tren, cau treo
hieu va » hieu qua
xay hoi » xa hoi, tay hoi, cay phoi
luc va » duc va, tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach _ dang xay hoi. ((hieu va) OR (lieu va)) cam luc va ((hanh di) or (hanh vi)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach _ dang xay hoi. ((hieu va) OR (lieu va)) cam luc va ((hanh di) OR (hanh vi)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach _ dang xay hoi. ((hieu va) OR (lieu va)) cam luc va ((hanh di) or (hanh vi)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach _ dang xay hoi. ((hieu va) OR (lieu va)) cam luc va ((hanh di) or (hanh vi)) cuu tre*.