Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
tan thanh » tran thanh, tang thanh, toan thanh
hieu van » hieu va, thien van, lieu va
dang xay » dang van, van xay
van cao » van dao, van bao, van hao
cua tre » cua te, cua triet, dua tren
cao duc » dao duc, cao suc, giao duc
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, lang van
cuu tre » cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty ((lang xa) OR (dang xay)) hoi. hieu van cao duc tan thanh van ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((lang xa) OR (dang xay)) hoi. hieu van cao duc tan thanh van ((cua tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((lang xa) OR (dang xay)) hoi. hieu van cao duc tan thanh van ((cua tre) or (cuu tre))*".