Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
van hanh » van thanh, ban hanh, van anh
cua viet » ca viet, hoa viet, cua vat
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
duc van » duc va, duc tan, duc manh
cuu tre » cua tre, cau tren, cau treo
x hoi » xa hoi, o hoi, 5 hoi

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 nang ((x hoi) or (x ho)). hieu vu cham duc van hanh vi ((cuu tre) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky nang ((x hoi) OR (x ho)). hieu vu cham duc van hanh vi ((cuu tre) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: tu cac ky nang ((x hoi) or (x ho)). hieu vu cham duc van hanh vi ((cuu tre) or (cua viet))*.