Perhaps you should try some spelling variations:
co sach » bo sach, cuon sach, hoc sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu ve » hieu van
hieu va » lieu va, hieu qua
cao luc » bao luc, cao duc, cao suc
va hang » van hang, va nang, va lang
hang vi » hang va, hanh vi, hang di
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach ty xang xa hoi. ((hieu ve) or (hieu va)) cao luc va hang vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ty xang xa hoi. ((hieu ve) OR (hieu va)) cao luc va hang vi cua tu.
• Adding a wildcard symbol may retrieve word variants: co sach ty xang xa hoi. ((hieu ve) or (hieu va)) cao luc va hang vi cua tu*.