UNE-EN 60027-3:2007 Letter symbols to be used in electrical technology -- Part 3: Logarithmic and related quantities, and their units (IEC 60027-3:2002).
2007UNE-EN 60027-3:2007 Letter symbols to be used in electrical technology -- Part 3: Logarithmic and related quantities, and their units (IEC 60027-3:2002).