Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh vi » hanh vi, thanh va, thanh ve
su sach » so sach, vu sach
cua tre » cuu tre, cua triet, dua tren
duc van » duc va, duc tan, duc manh
cao duc » dao duc, cao suc, giao duc
sach ky » sac ky, sach y, sach ty
qua cao » qua cac, qua ca, qua cai
mai hoi » mai khoi, dai hoi, lai hoi
ky tang » ky nang, ky dang, kho tang
ma hoi » xa hoi, ma hoa, me hoi
cua te » cua tu

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: su sach ky tang ((ma hoi) OR (mai hoi)). hieu qua cao duc van thanh vi ((cua tre) OR (cua te))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky tang ((ma hoi) OR (mai hoi)). hieu qua cao duc van thanh vi ((cua tre) or (cua te))~".
• Adding a wildcard symbol may retrieve word variants: su sach ky tang ((ma hoi) OR (mai hoi)). hieu qua cao duc van thanh vi ((cua tre) or (cua te))*.