@article{Char1970, 
     author = "Char, J.P.", 
     doi = "10.1049/piee.1970.0292", 
     journal = "Proceedings of the Institution of Electrical Engineers", 
     link = "http://digital-library.theiet.org/content/journals/10.1049/piee.1970.0292", 
     number = "8", 
     pages = "1655", 
     title = "Master circuit matrix", 
     uri = "http://digital-library.theiet.org/content/journals/10.1049/piee.1970.0292", 
     volume = "117", 
     year = "1970", 
}

Problems: 429