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
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, nang cao
cam tuc » cam tu, nam thuc, dam thuc
co viet » so viet, o viet, hoc viet
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang ma hoa. hieu van ((cam tuc) or (cam xuc)) van hanh vi ((cua viet) or (co viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang ma hoa. hieu van ((cam tuc) OR (cam xuc)) van hanh vi ((cua viet) OR (co viet)).
• Adding a wildcard symbol may retrieve word variants: so sach y nang ma hoa. hieu van ((cam tuc) or (cam xuc)) van hanh vi ((cua viet) or (co viet))*.