Whatever makes you feel right is a 'great book'... a typical Modernist, Protestant attitude.
Bishop Pivarunas was consecrated in the traditional Rite by a valid Bishop who was also consecrated in the traditional Rite, so there is no question of the validity of his episcopacy.
He doesn't go around kissing infidel holy books or bowing to Lutheran tables with heretics, so you try to dig up whatever gossip you can about him.
Funny how you'll recommend a book that takes shots at a legitimate Bishop of the Church and hints
at problems, but you won't accept the clear teaching of the Church about Popes (or papal claimants) who are material heretics.
Immaculate Heart of Mary, triumph soon.
Sacred Heart of Jesus, have mercy on us.