Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
hieu va » hieu qua
cuu tre » cua tre, cau tren, cau treo
soc va » loc va, doc va, goc va
vi cuu » vi luu, vinh cuu

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