Perhaps you should try some spelling variations:
xac danh » xac dinh, tac danh, sach danh
cua viet » hoa viet, cua vat, cua dieu
danh sai » dung sai, danh bat, danh dau
tu sach » thu sach, su sach, te sach
ca viet » va viet, hoa viet, san viet
thu xac » thau xay
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
co viet » so viet, o viet, hoc viet
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 sai ((cua viet) or (((ca viet) OR (co viet))))~.
• 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 sai ((cua viet) OR (((ca viet) OR (co viet)))).
• 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 sai ((cua viet) or (((ca viet) OR (co viet))))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ma hoi. hieu he nam thu xac danh sai ((cua viet) or (((ca viet) OR (co viet))))*.