Blue Cross, Blue Shield; "indemnity" or "service". 1953.
Chistensen
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D015142:Baltimore; D054598:Blue Cross Blue Shield Insurance Plans / Q000266:history*; D049673:History, 20th Century; D006801:Humans; D007350:Insurance, Hospitalization / Q000266:history*; D017061:Prepaid Health Plans / Q000266:history*