Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
thanh di » thanh doi, thanh de, thanh do
duc ban » duc tan, duc van, dua ban
hoc duc » hoc duoc, hoc nuoc, hoc thuc
van hoc » van hoa
te sach » toc sach
sach ky » sac ky, sach y, sach ty
ma hoi » mai hoi, me hoi, va 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 ky nang ((((ma hoi) OR (ma hoa))) OR (xa hoi)). hieu van hoc duc ban thanh di cua tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((((ma hoi) OR (ma hoa))) or (xa hoi)). hieu van hoc duc ban thanh di cua tu~".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((((ma hoi) OR (ma hoa))) or (xa hoi)). hieu van hoc duc ban thanh di cua tu*.