Your instructor may require you to format your paper or bibliography in AJPH (American Journal of Public Health) style. The AJPH follows AMA style. (You may also see this referred to as "APHA" style, since the American Public Health Association publishes AJPH.)
For help with AMA / AJPH style, see the following guide.
In addition to AMA style, many scientific journals ask authors to follow the Uniform Requirements for Manuscripts Submitted to Biomedical Journals. These guidelines were developed by the International Committee of Medical Journal Editors (ICMJE) at a meeting in 1978. The meeting was held in Vancouver, Canada; hence, this style is also sometimes referred to as "the Vancouver style".
For help with ICMJE style, see the link below.