Zeitschrift für angewandte Elektricitätslehre
- 1.1879 Google = MDZ München, Columbia = Google, California = Google
- 2.1880 Google = MDZ München, Columbia = Google, California = Google
- 3.1881 Google = MDZ München, Columbia = Google, California = Google
- 4.1882 Google = MDZ München, Columbia = Google, California = Google