Article: Evans, Nancy Goyne. 03//1973 Documented Fraktur in the Winterthur Collection: Part II. Antiques. 103 (3): 539-49.
• Published as pl. IV, pp. 547 and 549.Book: Earnest, Russell D. & Earnest, Corinne P. 1997 Papers for Birth Dayes: Guide to the Fraktur Artists and Scriveners. 2 vols. 909.
• Published on p. 625. For more info. on Portzline, see pp. 623-626.