I have done everything,i have got al sephirats,speaked with vivaldi and scrollwed all the quest inventory and i can't find this book,i havee only the quest book called ain soph aur.How can i get the other book?

have you looked in the cupboards of 'gramps' shack? you should be able to to buy both from vivaldi but i think gramps has a copy too (sorry if my info is inaccurate- it's been awhile since i've played)

Vivaldi should sell you the book. If you helped him earlier he would give you both. If you don't have that option, I believe there is a book seller (in the street between Shani's house and Thaler's house) who should have it.