Specific Rules #3 for Place of Publication (required) for the Volume for Individual Volumes With a Separate Title and Separate Authors/Editors 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.

An alternative is to use the place of publication and publisher likely to be most familiar to the audience of the reference list. For example, use the place of an American publisher for a US audience and a London publisher for a British one.

Según:

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

Related:

General Rules for Place of Publication (required) for the Volume for Individual Volumes With a Separate Title and Separate Authors/Editors Vancouver Style

Specific Rules #1 for Place of Publication (required) for the Volume for Individual Volumes With a Separate Title and Separate Authors/Editors Vancouver Style: Non-US cities

Specific Rules #2 for Place of Publication (required) for the Volume for Individual Volumes With a Separate Title and Separate Authors/Editors Vancouver Style: Joint publication

Specific Rules #3 for Place of Publication (required) for the Volume for Individual Volumes With a Separate Title and Separate Authors/Editors Vancouver Style: Multiple places of publication

Specific Rules #4 for Place of Publication (required) for the Volume for Individual Volumes With a Separate Title and Separate Authors/Editors Vancouver Style: No place of publication can be found

Examples for Place of Publication (required) for the Volume for Individual Volumes With a Separate Title and Separate Authors/Editors Vancouver Style