Perhaps you should try some spelling variations:
so sach » bo sach, co sach, hoc sach
cao luc » bao luc, cao duc, cao suc
so sanh » do sanh
xang xa » lang xa, mang xa, ang xa
hieu ve » hieu van
hang de » hoang de, hanh de, hang di
va hang » van hang, va nang, va lang
hieu va » lieu va, hieu qua
de cua » le cua, te cua, dieu cua
luc va » duc va, tuc va, loc va
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: ((so sach) OR (so sanh)) ty xang xa hoi. ((hieu ve) or (hieu va)) cao luc va hang de cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (so sanh)) ty xang xa hoi. ((hieu ve) OR (hieu va)) cao luc va hang de cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) OR (so sanh)) ty xang xa hoi. ((hieu ve) or (hieu va)) cao luc va hang de cua tu".
• Adding a wildcard symbol may retrieve word variants: ((so sach) OR (so sanh)) ty xang xa hoi. ((hieu ve) or (hieu va)) cao luc va hang de cua tu*.