Perhaps you should try some spelling variations:
sach doi » sach hoi, sach moi, sach dao
doi vang » doi mang, doi van, doi khang
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
thu van » thuc van, thuy van, tu van
hai cua » thai cua, hoi cua, lai cua
x hoi » xa hoi, o hoi, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach doi vang ((x hoi) or (x ho)). hieu van nam thu van hanh ((hai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach doi vang ((x hoi) OR (x ho)). hieu van nam thu van hanh ((hai cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: tu sach doi vang ((x hoi) or (x ho)). hieu van nam thu van hanh ((hai cua) or (dai cua)) tre*.