Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
danh di » danh du, xanh di, danh dien
va danh » va dinh, va dan, va hanh
hieu va » lieu va, hieu qua
cau tre » cau tren, cau treo, cau tra
nang xa » lang xa, nang ma, mang xa
va cam » va cham, va cac, va cao
cam tu » cam thu, nam tu, dam tu
di cau » da cau, diem cau

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) thu ((nang xa) OR (nang x)) hoi. hieu va cam tu va danh di cau tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) thu ((nang xa) OR (nang x)) hoi. hieu va cam tu va danh di cau tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) thu ((nang xa) OR (nang x)) hoi. hieu va cam tu va danh di cau tre*.