DIN IEC 60642:1988 Piezoelectric ceramic resonators and resonator units for frequency control and selection; standard values and conditions; measuring and test conditions; identical with IEC 60642, edition 1979
1988DIN IEC 60642:1988-04 Piezoelectric ceramic resonators and resonator units for frequency control and selection; standard values and conditions; measuring and test conditions; identical with IEC 60642, edition 1979
1988DIN IEC 60642:1988 Piezoelectric ceramic resonators and resonator units for frequency control and selection; standard values and conditions; measuring and test conditions; identical with IEC 60642, edition 1979