Kowalczyk, Stanisław. “PDHdtjtd Systemy PDH Ss: Sieci WAN Nowa Poprawka Tstjsttj”. DEMO 12304, no. 130 (February 8, 2022): 45–88. Accessed May 16, 2024. https://ojs.fimagis.pl/demo/article/view/69.