\input zb-basic \input zb-ioport \iteman{io-port 50279169} \itemau{Reis, T.; Willems, J. C.} \itemti{A balancing approach to the realization of systems with internal passivity and reciprocity} \itemso{Systems & Control Letters 60, No. 1, 69-74 (2011).} \itemcc{} \itemut{} \itemli{doi:10.1016/j.sysconle.2010.10.009} \end