Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, hoc sach, cuoc cach
toc sach » hoc sach, doc sach, thuoc sach
hang doi » hang loi, huong doi, hang tai
hang di » hang vi, hang dien, hang dich
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
tu nang » tru nang, tu nong, tu nano
cuu tre » cua tre, cau tren, cau treo
cac tu » cac thu, cach tu, cac du

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