"Biorhythm" is Bio-Nonsense.

George S. Thommen, Is This Your Day: How Biorhythm Helps You Determine Your Life Cycles ,(1973)

Ernest Jones, The Life and Work of Sigmund Freud ,(1953)

F. A. Brown, Gay Gaer Luce, Biological Rhythms in Human and Animal Physiology American Journal of Psychology. ,vol. 86, pp. 445- ,(1973) , 10.2307/1421454

John W. Shaffer, Biorhythms and Highway Crashes Archives of General Psychiatry. ,vol. 35, pp. 41- 46 ,(1978) , 10.1001/ARCHPSYC.1978.01770250043003

John H. Wolcott, Robert R. McMeekin, Robert E. Burgin, Robert E. Yanowitch, Correlation of general aviation accidents with the biorhythm theory Human Factors. ,vol. 19, pp. 283- 293 ,(1977) , 10.1177/001872087701900311

Colin S. Pittendrigh, Serge Daan, A Functional Analysis of Circadian Pacemakers in Nocturnal Rodents. I. The Stability and Lability of Spontaneous Frequency Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology. ,vol. 106, pp. 223- 252 ,(1976) , 10.1007/BF01417856