If you are writing an article for publication in a journal, you'll find the Instructions to Authors that indicate the format for citing your sources. Many journals may use standard citation styles, such as National Library of Medicine (NLM), American Medical Association (AMA), American Psychological Association (APA), or other styles. However, many journals also have a custom citation style that is closely related to a common citation style, with a few changes. Indeed, looking in Zotero's Style Repository, you'll find over 6,500 citation styles to select, with the majority of these focusing on particular journals.
APA citation style is one of the citation styles that is commonly used in health sciences journals and curriculums. APA style is used in journals such as:
The Purdue Owl provides extensive information on APA style, including a sample APA paper.