- http://en.wikipedia.org/wiki/Digital_Access_Carrier_System
- http://www.answers.com/topic/digital-loop-carrier
- http://hccc.ee.ccu.edu.tw/courses/datacom/lecture-vg/carrier.pdf
- http://annsgarden.com/poles/poles.htm
- http://www2.cs.uidaho.edu/~krings/CS420/Notes.S08/08-420-10.pdf
- http://www.google.hu/imgres?imgurl=http://www.fiber-optics.info/images/outside-plant.gif&imgrefurl=http://www.refly.cn/en/js.asp%3Fid%3D133&usg=___pOC5r_hVbpxRGtWIOF8j-TpAW8=&h=161&w=216&sz=10&hl=hu&start=1&um=1&itbs=1&tbnid=UHoC6yGde1cJWM:&tbnh=80&tbnw=107&prev=/images%3Fq%3Dtelecommunication%2BT1%2Bline%2Bconduit%2Bpoles%2Brepeater%26um%3D1%26hl%3Dhu%26client%3Dfirefox-a%26rls%3Dorg.mozilla:hu:official%26tbs%3Disch:1
- http://www.youtube.com/watch?v=UcI_Czmcn8Y
- http://tkne.net/downloads/power/cabels3/Underground%20cables.pdf