Niwano, Nikkyo Honzon : the object of workship of Rissho Kosei-kai / by Nikkyo Niwano ; [translated from the Japanese by Chido Takeda and Wilhelm Schiffer] - Tokio : [s.n.], 1969 - 95 p., [1] f. de làm. ; 19 cm LCCN: 17163