@article{oai:soar-ir.repo.nii.ac.jp:00013223,
 author = {松山,  潔},
 journal = {信州大学工学部研究報告},
 month = {Mar},
 note = {An apparatus to amplify the micro order d. c. voltages has been composed of an audio frequency amplifier, two telegraphic relays and a local oscillator. Its noise level is about 10⁻⁹ volt. The zero level shifting in this apparatus is prevented by the :use of a negative feed back thermo-junction circuit. Some of general considerations on the d. c. amplification are contained in this paper., Article, 信州大学工学部研究報告 2: 43-48(1953)},
 pages = {43--48},
 title = {直流増巾に就いて},
 volume = {2},
 year = {1953}
}