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
thuc va » thuc dan, thuc day
cuu tre » cua tre, cau tren, cau treo
hieu va » hieu qua
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
dan va » doan va, dan ca, ban va
va cuu » va cau, va chu, va huu

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. ((hieu va) or (lieu va)) nam ((thuc va) OR (thuc vat)) dan va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xay hoi. ((hieu va) OR (lieu va)) nam ((thuc va) OR (thuc vat)) dan va cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xay hoi. ((hieu va) or (lieu va)) nam ((thuc va) OR (thuc vat)) dan va cuu tre*".