1. Design and installation of first 20 kV spacer cable in Iran;Hagh,2011
2. 20 kV overhead lines with covered conductors;Panosch,2001
3. Compact 35 kV overhead lines with covered conductors;Podporkin,2005
4. Electric Conductor Wire Spacer and Method of Applying Same;Flower,1958
5. Coaxial Cable with Helical Insulating Spacer;Heinz,1964