Perhaps you should try some spelling variations:
hanh than » hanh han, hanh nhan, hanh phan
than cua » nhan cua, thai cua, ban cua
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
cua tre » cua te, cuu tre, cua triet
cao duc » dao duc, cao suc, giao duc
cam duc » cam xuc, pham duc, nam duoc
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
dai ky » dan ky, dai ly, sai ky
su dai » sau dai, si dai, su tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su dai ky dang xay hoi. hieu van ((cam duc) or (cao duc)) van hanh than cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su dai ky dang xay hoi. hieu van ((cam duc) OR (cao duc)) van hanh than cua tre.
• Adding a wildcard symbol may retrieve word variants: su dai ky dang xay hoi. hieu van ((cam duc) or (cao duc)) van hanh than cua tre*.