Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thai cua » than cua, tai cuc, tri cua
van hanh » van thanh, ban hanh, van ban
cua tre » cua te, cuu tre, cua triet
van anh » van thanh, tuan anh, van minh
dang xa » dang xay, lang xa, dang ha
cam duc » cam xuc, pham duc, nam duoc
ky dang » ky nang, ky danh
cao duc » dao duc, cao suc, giao duc
dai ky » dan ky, dai ly, sai ky

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

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