Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh sua » hinh su, hanh va, hanh tu
su sach » so sach, vu sach
van cam » van nam, van lam, van cau
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land
luc va » duc va, tuc va
loc va » hoc va
sua va » suat va, vua va, xua va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((y lang) OR (_ lang)) xa hoi. hieu van cam ((luc va) or (loc va)) hanh sua va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y lang) OR (_ lang)) xa hoi. hieu van cam ((luc va) OR (loc va)) hanh sua va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y lang) OR (_ lang)) xa hoi. hieu van cam ((luc va) or (loc va)) hanh sua va thiet".
• Adding a wildcard symbol may retrieve word variants: su sach ((y lang) OR (_ lang)) xa hoi. hieu van cam ((luc va) or (loc va)) hanh sua va thiet*.