Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
ly nang » ly hang, ly vang, ly quang
van bac » van ban, van bao, van hac
cua tre » cua te, cuu tre, cua triet
bo van » vo van, so van, do van
vi cua » vai cua, di 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: ((te sach) OR (toc sach)) ((ly nang) or (ky nang)) x hoi. hieu van bac bo van thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ((ly nang) OR (ky nang)) x hoi. hieu van bac bo van thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ((ly nang) or (ky nang)) x hoi. hieu van bac bo van thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ((ly nang) or (ky nang)) x hoi. hieu van bac bo van thanh vi cua tre*.