[1]
Barwise, Jon, Admissible Sets and Structures, Springer, Berlin, 1975.

[2]
Beany, Michael and Reck, Erich H., editors, Gottlob Frege, Critical Assessments of Leading Philosophers, Routledge, London and New York, 2005, Four volumes.

[3]
Boolos, George,
*The iterative conception of set*
. The Journal of Philosophy, vol. 68 (1971), pp. 215–232, Reprinted in [5].

[4]
Boolos, George,
*Iteration again*
. Philosophical Topics, vol. 17 (1989), pp. 5–21, Reprinted in [5].

[5]
Boolos, George, Logic, Logic, and Logic, Harvard University Press, Cambridge, MA, 1998, Edited by Jeffrey, Richard.

[6]
Burgess, John P.,Fixing Frege, Princeton Monographs in Philosophy, Princeton University Press, Princeton, 2005.

[7]
Cook, Roy T.,
*Iteration one more time*
. Notre Dame Journal of Formal Logic, vol. 44 (2003), no. 2, pp. 63–92, Reprinted in [8].

[8]
Cook, Roy T., editor, The Arché Papers on the Mathematics of Abstraction, The Western Ontario Series in Philosophy of Science, vol. 71, Springer, Berlin, 2007.

[9]
Demopoulos, William, editor, Frege’s Philosophy of Mathematics, Harvard University Press, Cambridge, 1995.

[10]
Devlin, Keith J., Constructibility, Perspectives in Mathematical Logic, Springer, Berlin, 1984.

[11]
Dummett, Michael, Frege: Philosophy of Mathematics, Harvard University Press, Cambridge, 1991.

[12]
Feferman, Solomon, *Systems of predicative analysis*, this Journal, vol. 29 (1964), pp. 1–30.

[13]
Feferman, Solomon,
*Predicativity*
, The Oxford Handbook of Philosophy of Mathematics and Logic (Shapiro, Stewart, editor), Oxford University Press, Oxford, 2005, pp. 590–624.

[14]
Ferreira, Fernando and Wehmeier, Kai F.,
*On the consistency of the*
*-CA fragment of Frege’s Grundgesetze*
. Journal of Philosophical Logic, vol. 31 (2002), no. 4, pp. 301–311.

[15]
Frege, Gottlob, Grundgesetze der Arithmetik: Begriffsschriftlich abgeleitet, Pohle, Jena, 1893, 1903, Two volumes. Reprinted in [16].

[16]
Frege, Gottlob, Grundgesetze der Arithmetik: Begriffsschriftlich abgeleitet, Olms, Hildesheim, 1962.

[17]
Frege, Gottlob, Basic Laws of Arithmetic, Oxford University Press, Oxford, 2013, Translated by Ebert, Philip A. and Rossberg, Marcus.

[18]
Friedman, Harvey M.,
*Some systems of second-order arithmetic and their use*
, Proceedings of the International Congress of Mathematicians, Vancouver 1974, vol. 1, 1975, pp. 235–242.

[19]
Gitman, Victoria, Hamkins, Joel David, and Johnstone, Thomas A., *What is the theory ZFC without powerset?*, arXiv:1110.2430, 2011.

[20]
Hale, Bob and Wright, Crispin, The Reason’s Proper Study, Oxford University Press, Oxford, 2001.

[21]
Heck, Richard G. Jr.,
*The consistency of predicative fragments of Frege’s Grundgesetze der Arithmetik*
. History and Philosophy of Logic, vol. 17 (1996), no. 4, pp. 209–220.

[22]
Heinzmann, Gerhard, Poincaré, Russell, Zermelo et Peano. Textes de la discussion (1906-1912) sur les fondements des mathématiques: Des antinomie à la prédicativié, Blanchard, Paris, 1986.

[23]
Hodes, Harold, *Where do sets come from?* this Journal, vol. 56 (1991), no. 1, pp. 150–175.

[24]
Hodges, Wilfrid, Model Theory, Encyclopedia of Mathematics and its Applications, vol. 42, Cambridge University Press, Cambridge, 1993.

[25]
Jech, Thomas, Set Theory, Springer Monographs in Mathematics, Springer, Berlin, 2003, The Third Millennium Edition.

[26]
Björn Jensen, R.,
*The fine structure of the constructible hierarchy*
. Annals of Mathematical Logic, vol. 4 (1972), pp. 229–308.

[27]
Kechris, Alexander S., Classical Descriptive Set Theory, Graduate Texts in Mathematics, vol. 156, Springer, New York, 1995.

[28]
Kripke, Saul, *Transfinite recursion on admissible ordinals I, II*, this Journal, vol. 29 (1964), no. 3, pp. 161–162.

[29]
Kunen, Kenneth, Set Theory, Studies in Logic and the Foundations of Mathematics, vol. 102, North-Holland, Amsterdam, 1980.

[30]
Kunen, Kenneth, Set Theory, College Publications, London, 2011.

[31]
Parsons, Terence,
*On the consistency of the first-order portion of Frege’s logical system*
. Notre Dame Journal of Formal Logic, vol. 28 (1987), no. 1, pp. 161–168, Reprinted in [9].

[32]
Alan Platek, Richard, Foundations of Recursion Theory, Unpublished Dissertation, Stanford University, Stanford, CA, 1966.

[33]
Sacks, Gerald E., Higher Recursion Theory, Perspectives in Mathematical Logic, Springer, Berlin, 1990.

[34]
Schindler, Ralf and Zeman, Martin,
*Fine structure*
, Handbook of Set Theory (Foreman, Matthew and Kanamori, Akihiro, editors), vol. 1, Springer, Berlin, 2010, pp. 605–656.

[35]
Shoenfield, Joseph R.,
*The problem of predicativity*
, Essays on the foundations of mathematics, Magnes Press, Jerusalem, 1961, pp. 132–139.

[36]
Shoenfield, Joseph R.,
*Chapter 9: Set theory*
, Mathematical Logic, Addison-Wesley, Reading, 1967, pp. 238–315.

[37]
Shoenfield, Joseph R.,
*Axioms of set theory*
, Handbook of Mathematical Logic (Barwise, Jon, editor), Studies in Logic and the Foundations of Mathematics, vol. 90, North-Holland, Amsterdam, 1977.

[38]
Simpson, Stephen G.,
*Short course on admissible recursion theory*
, Generalized recursion theory II, Studies in Logic and the Foundations of Mathematics, vol. 94, North-Holland, Amsterdam, 1978, pp. 355–390.

[39]
Simpson, Stephen G., Subsystems of Second Order Arithmetic, second edition, Cambridge University Press, Cambridge, 2009.

[40]
Walsh, Sean,
*Comparing Hume’s Principle, Basic Law V and Peano arithmetic*
. Annals of Pure and Applied Logic, vol. 163 (2012), pp. 1679–1709.

[41]
Walsh, Sean, *The strength of predicative abstraction*, arXiv:1407.3860, 2014.

[42]
Walsh, Sean,
*Predicativity, the Russell-Myhill paradox, and Church’s intensional logic*
. Journal of Philosophical Logic, forthcoming.

[43]
Weyl, Hermann, Das Kontinuum. Kritische Untersuchungen über die Grundlagen der Analysis., Veit, Leipzig, 1918.