Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tac, cac nuoc
va hang » van hang, va nang, va lang
hang di » hang doi, hang vi, hang dien
y lang » _ lang, tay lang, yen lang
o lang » hoa lang, hoi lang
cac tu » cac thu, cach tu, cac du
di va » dai va, di vao, doi va
thiet » thieu

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: tu sach ((y lang) OR (o lang)) xa hoi. hieu ve ((cac tuc) OR (cac tu)) va hang di va thiet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y lang) or (o lang)) xa hoi. hieu ve ((cac tuc) OR (cac tu)) va hang di va thiet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y lang) or (o lang)) xa hoi. hieu ve ((cac tuc) OR (cac tu)) va hang di va thiet*.