NLM style was created and is maintained by the National Library of Medicine. It is commonly used when publishing in the discipline of medicine and health sciences.
2nd edition - Citing Medicine provides assistance to authors in compiling lists of references for their publications, to editors in revising such lists, to publishers in setting reference standards for their authors and editors, and to librarians and others in formatting bibliographic citations.
Citing Medicine: The NLM Style Guide for Authors, Editors, and Publishers by 