Perhaps you should try some spelling variations:
hang dien » quang dien, nhan dien, sang dieu
toc sach » hoc sach, doc sach, thuoc sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
nang xa » nang x, lang xa, nang ma
hieu va » lieu va
cuu tre » cua tre, cau tren, cau treo
cam tu » cam thu, nam tu, dam tu

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