Fong, Paul J., Configuring Cisco Voice Over IP Paul J. Paul J, Eric Knipp & David Gray... et. al. - 2nd ed. - Navi Mumbai : Shroff Publishers & Distributors PVT LTD, c2001. - xxxi, 543 p.: [36] ISBN: 8173666245 Dewey Class. No.: 004.69 / FON/CON