Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
thanh di » thanh doi, thanh de, thanh do
toc sach » hoc sach, doc sach, thuoc sach
duc van » duc va, duc tan, duc manh
hoc duc » hoc duoc, hoc nuoc, hoc thuc
van hoc » van hoa
ma hoi » mai hoi, ma hoa, me hoi
di cua » dai cua, doi cua, de cua
cua tu » cua tuc, cua su, cua cu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang ((ma hoi) OR (xa hoi)). hieu van hoc duc van thanh di cua tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang ((ma hoi) or (xa hoi)). hieu van hoc duc van thanh di cua tu~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky nang ((ma hoi) or (xa hoi)). hieu van hoc duc van thanh di cua tu*.