Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
ly nang » ky nang, ly hang, ly vang
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, v nang, may nang
cam tu » cam thu, nam tu, dam tu
tu van » tu 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 sach ((y nang) or (ly nang)) xa hoi. hieu van cam tu van hanh vi ((cua tre) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ly nang)) xa hoi. hieu van cam tu van hanh vi ((cua tre) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) or (ly nang)) xa hoi. hieu van cam tu van hanh vi ((cua tre) or (cua viet))*.