MorrisD. G. O., The external characteristics of a.c. power sources. Int. J. elect. Engng Educ.1, 205 (1963). (In section 4.2 of this paper, the penultimate line should refer to a capacitive load)
2.
MorrisD. G. O., Ideal active elements. J. Instn elect. Engrs3, 272 (May 1957)