There is an illustration of St. John Stone by János Hajnal in "Il Fascino di Dio: Profili de Agiografia Agostiniana" by Fernando Rojo Martínez, O.S.A.
The illustration of St. John Stone by János Hajnal appears in the book "Il Fascino di Dio: Profili de Agiografia Agostiniana" authored by Fernando Rojo Martínez, O.S.A.