Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
cua viet » hoa viet, cua vat, cua dieu
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
ca viet » va viet, co viet, hoa viet
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa

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 ty nang ma hoi. hieu hien ((cac nuoc) or (cam xuc)) van hanh vi ((cua viet) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ma hoi. hieu hien ((cac nuoc) OR (cam xuc)) van hanh vi ((cua viet) OR (ca viet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ma hoi. hieu hien ((cac nuoc) or (cam xuc)) van hanh vi ((cua viet) or (ca viet))*.