Specific Rules #3 for Place of Publication (required) to Citing Entire Reports Vancouver Style: Multiple places of publication

If more than one place of publication is found, use the first one or the one set in the largest type or in bold type. Do not give multiple places.

As an option, if one place is a US city and the other(s) are not, use the US city.

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Citing Medicine: The NLM Style Guide for Authors, Editors, and Publishers [Internet]. 2nd edition. Chapter 4: Scientific and Technical Reports

Related:

General Rules for Place of Publication (required) to Citing Entire Reports Vancouver Style

Specific Rules #1: Non-US cities

Specific Rules #2: Joint publication

Specific Rules #3: Multiple places of publication

Specific Rules #4: No place of publication can be found

Examples for Place of Publication (required) to Citing Entire Reports Vancouver Style