Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
van thanh » van tuan
hieu van » hieu va, thien van, lieu va
thai cua » than cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
cam duc » cam xuc, cao duc, nam duoc
su hai » su tai
hai ky » thai ky, hoi ky, hai ly

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

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