Perhaps you should try some spelling variations:
thanh di » thanh doi, thanh de, thanh do
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te sach
van bac » van ban, van bao, van hac
van cac » van hac, van cau, dan cac
cua tre » cua te, cuu tre, cua triet
ty hang » ly hang, thi hang, thu hang
luc va » duc va, tuc va, loc va
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, x ho

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 ((ty hang) or (ty xang)) x hoi. hieu ((van cac) OR (van bac)) luc va thanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty hang) OR (ty xang)) x hoi. hieu ((van cac) OR (van bac)) luc va thanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty hang) or (ty xang)) x hoi. hieu ((van cac) OR (van bac)) luc va thanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty hang) or (ty xang)) x hoi. hieu ((van cac) OR (van bac)) luc va thanh di cua tre*.