Which of the following items of evidence is LEAST likely to be admitted without a supporting witness?
In a libel action, a copy of a newspaper purporting to be published by Defendant Newspaper Publishing Company.  In a case involving contaminated food, a can label purporting to identify the canner as Defendant Company.  In a defamation case, a document purporting to be a memorandum from the Defendant Company president to "All Personnel," printed on Defendant Company's letterhead.  In a case involving injury to a pedestrian, a pamphlet on stopping distances issued by the State Highway Departmen