David Howie, "Interpreting Probability: Controversies and Developments in the Early Twentieth Century" (Cambridge University Press, 2002)
Maria Carla Galavotti. "Harold Jeffreys' Probabilistic Epistemology: Between Logicism And Subjectivism". British Journal for the Philosophy of Science, 54(1):43–57 (March 2003). (A review of Jeffreys' approach to probability; includes remarks on R.A. Fisher, Frank P. Ramsey, and Bruno de Finetti. Also online: )
Bertha Swirles, Reminiscences and Discoveries: Harold Jeffreys from 1891 to 1940, Notes and Records of the Royal Society of London, Vol. 46, No. 2, pp. 301–308 (1992).
