एपीए उद्धरण

Ed Tittel. (1997). ISDN Clearly Explained. AP Professional.

शिकागो स्टाइल उद्धरण

Ed Tittel. ISDN Clearly Explained. AP Professional, 1997.

एमएलए उद्धरण

Ed Tittel. ISDN Clearly Explained. AP Professional, 1997.