If you're citing in MLA style, check out the interview section of Purdue Online Writing Lab's MLA Formatting and Style Guide. The guide breaks down how to properly cite a personal interview, published interviews, and more.
If you're citing in APA style, don't include any form of personal communication (e.g., emails, interviews, etc.) in your references. You'll only cite these resources in-text. Purdue OWL's APA Formatting and Style Guide has more information on how to handle these types of citations.