1. Experience of geomagnetic field recording with a fluxgate magnetometer having a bridge sensor;Bergmark,1984
2. Seriya kvartsevykh magnitnykh variometrov;Bobrov;Geomagn. i. Aeronom.,1962
3. Komponentniye bloki variometrov;Bobrov;Geomagnitniye Issledovaniya,1982
4. The digital recording system operated at the U.K. magnetic observatories;Forbes,1984
5. An intelligent magnetic recording system;Hegymegi,1984