"Information resources reflect their creators' expertise and credibility" (ACRL 2015).
This essentially means that the resource you're looking at and using as a source of your research reflects the authors' credibility and expertise in the topic. This means you, too. When you incorporate expert research and sources in your papers, that reflects on your credibility as well.
Authority can be constructed through subject expertise (scholarship), social position (public office), and experience (participation in an event).
Who might be an authority on yoga and pain relief and where will they be publishing their work?