According to the IEEE Standards Style manual, no citation is necessary for interviews and other “non-recoverable” information. Personal communication and other “nonrecoverable” information include telephone conversations, interviews, e-mails and letters. The IEEE style recommends that this type of correspondence be identified within the text of the document.
Additionally, do not refer to professional titles such as “Dr.” or “PhD” or even titles like U.S. Surgeon General, but do include personal titles such as “Jr.” or “III” after the surname.
In a personal interview, Bill Gates, explained why he recently pledged $4 billion for third world medicines.