Interviews, telephone conversations, email, letters and lectures are oral sources while discussion forums on the internet are treated as printed electronic sources. When it comes to referencing oral sources you must have the consent of the persons concerned.
According to the Harvard system the oral sources should not be in the list of references at the end. Use a footnote instead. Number the footnotes continuously, even if the same source is used repeatedly.
Please note that interviews and surveys should not be handled like other oral or written sources. How they should be handled depends on subject discipline and therefore we refer you to the guidelines given at your institution or consult your supervisor/teacher. You can also find this type of information in methodology books.
N.B. Please treat your informants with confidentiality. Do not use their real names. It is rather common to use a system such as "informant 1", "informant 2" etcetera. Please note that even if you use fictitious names for your informants they may be identified if you state their company in connection to their working duties. Especially when it comes to smaller organizations. Consult your supervisor regarding issues about personal data.
In the text you write:
Halse (1) claims that the type of services that Aerotech Telub offer is an important aspect of Saab’s core organization.
Näverå (2) argues that e-books should be promoted….
In the footnote you write:
(1) Bengt Halse CEO at Saab, interview April 11 2002.
(2 )Elisabeth Näverå Librarian Högskolan Väst, e-mail August 19 2011.