found: Gerling, H. Thoughts of an outstanding entrepreneur, c2000:p. 10 (Gerling Group) p. 11 (Gerling Insurance Group) p. 23, etc. (Gerling-Konzern) p. 25 (history of the Group from 1904-1954) p. 137 (holding company, Gerling-Konzern Versicherungs-Beteiligungs-Aktiengesellschaft) p. 203-206 (further history of the Group and its companies)
found: Architektur der 50er Jahre, 1994:t.p. (Gerling-Konzern)
found: Dt. Adressbuch, 1995(under Köln: Gerling Konzern; composed of a number of insurance companies, e.g., Allgemeine Versicherungs-AG, Lebensversicherung-AG)
