Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh va, hanh tai, hanh van
ky sang » ky nang, ky dang, duy sang
ky tang » ky nang, ky dang, kho tang
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ((ky sang) or (ky tang)) ma hoi. hieu van cam xuc va ((hanh vai) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ((ky sang) OR (ky tang)) ma hoi. hieu van cam xuc va ((hanh vai) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ((ky sang) or (ky tang)) ma hoi. hieu van cam xuc va ((hanh vai) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu cac ((ky sang) or (ky tang)) ma hoi. hieu van cam xuc va ((hanh vai) OR (hanh vi)) cua tre*.