P. Kacprzak, M. Kaleta, P. Pałka, K. Smolira, E. Toczyłowski, and T. Traczyk, “Application of open multi-commodity market data model on the communication bandwidth market”, JTIT, vol. 30, no. 4, pp. 45–50, Dec. 2007, doi: 10.26636/jtit.2007.4.850.