Perhaps you should try some spelling variations:
xac danh » xac dinh, sach danh, cac doanh
cua viet » ca viet, hoa viet, cua dieu
tac danh » sach danh, cac doanh, cac dan
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu he » hieu ve, hiem he, hieu le
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
he nam » ha nam, nghe nam
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 ky sang ma hoi. hieu he nam thu ((xac danh) or (tac danh)) sai ((cua viet) OR (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang ma hoi. hieu he nam thu ((xac danh) OR (tac danh)) sai ((cua viet) OR (cua vat)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky sang ma hoi. hieu he nam thu ((xac danh) or (tac danh)) sai ((cua viet) OR (cua vat))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ma hoi. hieu he nam thu ((xac danh) or (tac danh)) sai ((cua viet) OR (cua vat))*.