The biological effects of magnetic fields: a survey.
R.O. BECKER. Med. Electron. Biol. Eng. 1: 293–303, 1963. [PDF]

The direct current field: a primitive control and communication system related to growth processes.
R.O. BECKER. in Proc. XVI Int. Congress Zool. 3: 179–184, 1963. [PDF]