Montejo-Garai, J. R., J. A. Ruiz-Cruz, and J. M. Rebollar,  "Synthesis of Symmetric and Asymmetric Singly-Terminated Elliptic Ladder Filters for Multiplexing Applications",  International Journal of RF and Microwave Computer-Aided Engineering, vol. 19, no. 4, pp. 443-452, July, 2009.