Perhaps you should try some spelling variations:
thanh than » thanh thanh, thanh thang, thanh toan
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
cuu tre » cau tren, cau treo
cao duc » dao duc, cao suc, giao duc
cua tre » cua te, cua triet, dua tren
duc van » duc va, duc tan, duc manh
van cao » van dao, van bao, van hao
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
su tai » su thi, tu tai
su sai » su hai, su dai, su mai

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

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