Works that cannot be traced by readers are cited in the text as personal communications.
Personal communications include:
- emails,
- text messages, online chats or direct messages,
- personal interviews s (i.e., not conducted in the context of research),
- (telephone) conversations,
- live speeches or lessens,
- nonarchived social media livestreams (e.g., Instagram Live, Twitter Spaces) or content from private accounts,
- memos, letters or internship documents, and so on.
Personal communication is cited only in the text, because the source of the information is cannot be traced by the reader.
Provide initials and surname (in that order) of the person you are citing, and give the exact date (Month Day, Year).
Narrative citation: According to Mr Jan Janssen (personal communication, July 17, 2020), this is not the case.
Parenthetical citation: During the lecture (J. Janssen, personal communication, July 17, 2020), it was told that this is not the case.
If a document is available online but only accessible after logging in (e.g. on an intranet), the information is only available to a limited number of people. First consider whether the content of the document is confidential, if so, refer to it as a personal communication.
If it is general information, and the reader or reviewer has access to the information behind the login, it makes sense to include an entry with URL in the reference list. If this is not the case, choose to refer to it as a personal communication.