Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh tri » thanh tri, hanh tai, hanh trinh
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
cao duc » dao duc, cao suc, giao duc
van cao » van dao, van bao, van hao
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
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 dang xa hoi. hieu van cao duc van ((hanh tri) or (hanh chinh)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sai) OR (su tai)) ky dang xa hoi. hieu van cao duc van ((hanh tri) OR (hanh chinh)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sai) OR (su tai)) ky dang xa hoi. hieu van cao duc van ((hanh tri) or (hanh chinh)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sai) OR (su tai)) ky dang xa hoi. hieu van cao duc van ((hanh tri) or (hanh chinh)) cua tre*.