Slow electrons—not relativistic?

Two recent publications have cast doubt on the importance of relativistic effects in the scattering of slow electrons (2 to 200 eV). The claim that relativistic factors played an important part in such reactions was made by H. N. Browne and Ernst Bauer [Phys. Rev. Letters 16, 495 (1966)] and reported in PHYSICS TODAY, May 1966, page 82. Objections have been entered by Manuel Rotenberg [Phys. Rev. Letters 16, 969 (1966)] and by Larry Spruch [Phys. Rev. Letters 16, 1137 (1966)].