Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
van hanh » ban hanh, van anh, van ban
cua viet » hoa viet, cua vat, cua dieu
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
ca viet » va viet, co viet, hoa viet
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho

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 ky nang x hoi. hieu ve cac duc ((van hanh) OR (van thanh)) gia ((cua viet) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu ve cac duc ((van hanh) OR (van thanh)) gia ((cua viet) OR (ca viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu ve cac duc ((van hanh) OR (van thanh)) gia ((cua viet) or (ca viet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu ve cac duc ((van hanh) OR (van thanh)) gia ((cua viet) or (ca viet))*.