Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh hai » thanh phan, thanh hoa, thanh san
cua tre » cua te, cuu tre, cua triet
ky tang » ky nang, ky dang, kho tang
hai cua » thai cua, dai cua, hoi cua
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, nam duoc
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, me hoi

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

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