Perhaps you should try some spelling variations:
thien van » thi van
hanh tri » thanh tri, hanh tai, hanh trinh
hieu van » hieu va, lieu va, hieu ve
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
cao duc » dao duc, cao suc, giao duc
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
sai ky » sac ky
su sai » su tai, su hai, su dai

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 ky dang xa hoi. ((hieu van) OR (thien van)) cao duc van ((hanh tri) or (canh tranh)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky dang xa hoi. ((hieu van) OR (thien van)) cao duc van ((hanh tri) OR (canh tranh)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sai ky dang xa hoi. ((hieu van) OR (thien van)) cao duc van ((hanh tri) or (canh tranh)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sai ky dang xa hoi. ((hieu van) OR (thien van)) cao duc van ((hanh tri) or (canh tranh)) cua tre*.