Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van nang » van quang, van ban, van dong
thanh di » thanh doi, thanh de, thanh do
va thanh » gia thanh, ban thanh, va tinh
cao tuc » dao tuc, cao duc, cao suc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
vu nang » vuc nang, va nang, vu dang
va cao » va cac, va co, va dao
tuc va » thuc va, truc va, tuc xa
di cua » dai cua, doi cua, de 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: toc sach ((van nang) or (vu nang)) ((x hoi) or (x ho)). hieu va cao tuc va thanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((van nang) OR (vu nang)) ((x hoi) OR (x ho)). hieu va cao tuc va thanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((van nang) or (vu nang)) ((x hoi) or (x ho)). hieu va cao tuc va thanh di cua tre*.