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