[1] Bahaa E. A. Saleh, Malvin Carl Teich. “Fundamentals of Photonics”. John Wiley &  Sons, ISBNs: 0-471-83965-5 (Hardback); 0-471-2-1374-8 (Electronic) (Capitulo 8 )

[2] The Cable and Telecommunications Handbook v2, (2009) (Capitulo 5)