Because AMA formatting is dependent on the publisher where you may be submitting research, it is helpful to pick a source for guidelines and be consistent with those guidelines. A few starting points are suggested below:
The International Committee of Medical Journal Editors (ICMJE) offers guidance to authors in its publication Recommendations for the Conduct, Reporting, Editing and Publication of Scholarly Work in Medical Journals (ICMJE Recommendations), which was formerly the Uniform Requirements for Manuscripts. The recommended style for references is based on the National Information Standards Organization NISO Z39.29-2005 (R2010) Bibliographic References as adapted by the National Library of Medicine for its databases.
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.