| A. A. W. | Lewis Carroll: Alice’s Adventures in Wonderland, London, 1908. [This book was first published much earlier, but this was the edition used by Mr. R*ss*ll. The same applies to H. S. and T. L. G.] |
| A. C. P. | John Henry Blunt (ed. by): The Annotated Book of Common Prayer, London, new edition, 1888. |
| A. d. L. | Ernst Schröder: Vorlesungen über die Algebra der Logik, Leipzig, vol. i., 1890; vol. ii. (two parts), 1891 and 1905; vol. iii.: Algebra und Logik der Relative, 1895. |
| E. N. | Richard Dedekind: Essays on the Theory of Numbers, Chicago and London, 1901. |
| E. L. L. | William Stanley Jevons: Elementary Lessons in Logic, Deductive and Inductive. With copious Questions and Examples, and a Vocabulary of Logical Terms, London, 24th ed., 1907 [first published in 1870]. |
| E. u. I. | Ernst Mach: Erkenntnis und Irrtum: Skizzen zur Psychologie der Forschung, Leipzig, 1906. |
| F. L. | Augustus De Morgan: Formal Logic: or The Calculus of Inference, Necessary and Probable, London, 1847. |
| Fm. L. | John Neville Keynes: Studies and Exercises in Formal Logic, 4th ed., London, 1906. |
| Gg. | Gottlob Frege: Grundgesetze der Arithmetik begriffschriftlich abgeleitet, Jena, vol. i., 1893; vol. ii., 1903. |
| Gl. | Gottlob Frege: Die Grundlagen der Arithmetik: eine logisch-mathematische Untersuchung über den Begriff der Zahl, Breslau, 1884. |
| G. u. E. | G. Heymans: Die Gesetze und Elemente des wisenschaftlichen Denkens, Leiden, vol. i., 1890; vol. ii., 1894. |
| H. J. | The Hibbert Journal: a Quarterly Review of Religion, Theology and Philosophy, London and New York. |
| H. S. | Lewis Carroll: The Hunting of the Snark: an Agony in Eight Fits, London, 1911. |
| M. | The Monist: a Quarterly Magazine Devoted to Science and Philosophy, Chicago and London. |
| Md. | Mind: a Quarterly Review of Psychology and Philosophy, London and New York. |
| Pa. Ma. | Alfred North Whitehead and Bertrand Russell: Principia Mathematica, vol. i., Cambridge, 1910. [Other volumes were published in 1912 and 1913.] |
| P. E. | Bertrand Russell: Philosophical Essays, London and New York, 1910. |
| Ph. L. | Bertrand Russell: A Critical Exposition of the Philosophy of Leibniz, with an Appendix of Leading Passages, Cambridge, 1900. |
| P. M. | Bertrand Russell: The Principles of Mathematics, vol. i., Cambridge, 1903. |
| R. M. M. | Revue de Métaphysique et de Morale, Paris. |
| S. B. | Lewis Carroll: Sylvie and Bruno, London, 1889. |
| S. L. | John Venn: Symbolic Logic, London, 1881; 2nd ed., 1894. |
| S. o. S. | William Stanley Jevons: The Substitution of Similars, the True Principle of Reasoning derived from a Modification of Aristotle’s Dictum, London, 1869. |
| T. L. G. | Lewis Carroll: Through the Looking-Glass, and what Alice found there, London, 1911. |
| Z. S. | Gottlob Frege: Ueber die Zahlen des Herrn H. Schubert, Jena, 1899. |