Leonard Forrer: Breuer, Peter (Germ.). In: Biographical Dictionary of Medallists. Coin, gem, and seal-engravers, mint-masters, &c., ancient and modern, with references to their works B.C. 500 – A.D. 1900. Band7: Supplement A–L. Spink & Son Ltd, London 1923, S.123 (Textarchiv – Internet Archive).