Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
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Credit
Army Blood Transfusion Service, Royal Army Medical Corps. Use of Bat symbol on vehicles, uniform, equipment, direction boards, etc., 1939/45, typescript paper by John G. Bailey. Attribution-NonCommercial 4.0 International (CC BY-NC 4.0). Source: Wellcome Collection.