Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thu sach » tu sach, thuat sach, thuoc sach
thanh di » thanh doi, thanh de, thanh do
sach ty » sach y, sach tu, sach thu
hoc duc » hoc duoc, hoc nuoc, hoc thuc
cua tre » cua te, cuu tre, cua triet
hoc dua » hoc lua, hoc du, hoc sua
hieu va » lieu va, hieu qua
xang x » nang x
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: thu sach ty xang x hoi. hieu va ((((hoc dua) OR (hoc duc))) or (hoc cua)) van thanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty xang x hoi. hieu va ((((hoc dua) OR (hoc duc))) OR (hoc cua)) van thanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty xang x hoi. hieu va ((((hoc dua) OR (hoc duc))) or (hoc cua)) van thanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ty xang x hoi. hieu va ((((hoc dua) OR (hoc duc))) or (hoc cua)) van thanh di cua tre*.