Perhaps you should try some spelling variations:
hang dai » hoang dai, hang tai, hang dau
hoc sach » hoc sinh, hoc cac, hoc anh
co sach » bo sach, cuon sach
hieu va » lieu va, hieu qua
va hang » van hang, va nang, va lang
xang xa » lang xa, mang xa, ang xa
hieu ve » hieu van
cao luc » bao luc, cao duc, cao suc
luc va » duc va, tuc va, loc va
cua tu » cua tuc, cua su, cua cu
y xang » ty xang

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) OR (hoc sach)) y xang xa hoi. ((hieu ve) or (hieu va)) cao luc va hang dai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((co sach) OR (hoc sach)) y xang xa hoi. ((hieu ve) OR (hieu va)) cao luc va hang dai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((co sach) OR (hoc sach)) y xang xa hoi. ((hieu ve) or (hieu va)) cao luc va hang dai cua tu".
• Adding a wildcard symbol may retrieve word variants: ((co sach) OR (hoc sach)) y xang xa hoi. ((hieu ve) or (hieu va)) cao luc va hang dai cua tu*.