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 di, hang loi, huong doi
doi cua » dai cua, hoi cua
va hang » van hang, va nang, va lang
cac thu » cach thuc, cac thoi
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
tu nang » tru nang, tu nong, tu nano
cac tu » cach tu, cac du, tac 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) or (nuoc sach)) tu nang xa hoi. hieu va ((cac tu) OR (cac thu)) va hang doi cua 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) OR (cac thu)) va hang doi cua 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) OR (cac thu)) va hang doi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (nuoc sach)) tu nang xa hoi. hieu va ((cac tu) OR (cac thu)) va hang doi cua tre*.