A geometric interpretation of an equality by Sylvester. - Claudio Perelli Cippo (Discret. Math., 1997)

Double graphs. - Emanuele Munarini; Claudio Perelli Cippo; Andrea Scagliola; Norma Zagaglia Salvi (Discret. Math., 2008)

On some colorings of a double graph. - Emanuele Munarini; Claudio Perelli Cippo (Electron. Notes Discret. Math., 2013)