Rathjen, Michael. "Remarks on Barr’s Theorem: Proofs in Geometric Theories".
Concepts of Proof in Mathematics, Philosophy, and Computer Science, edited by Dieter Probst and Peter Schuster, Berlin, Boston: De Gruyter, 2016, pp. 347-374.
https://doi.org/10.1515/9781501502620-019Rathjen, M. (2016). Remarks on Barr’s Theorem: Proofs in Geometric Theories. In D. Probst & P. Schuster (Ed.),
Concepts of Proof in Mathematics, Philosophy, and Computer Science (pp. 347-374). Berlin, Boston: De Gruyter.
https://doi.org/10.1515/9781501502620-019Rathjen, M. 2016. Remarks on Barr’s Theorem: Proofs in Geometric Theories. In: Probst, D. and Schuster, P. ed.
Concepts of Proof in Mathematics, Philosophy, and Computer Science. Berlin, Boston: De Gruyter, pp. 347-374.
https://doi.org/10.1515/9781501502620-019Rathjen, Michael. "Remarks on Barr’s Theorem: Proofs in Geometric Theories" In
Concepts of Proof in Mathematics, Philosophy, and Computer Science edited by Dieter Probst and Peter Schuster, 347-374. Berlin, Boston: De Gruyter, 2016.
https://doi.org/10.1515/9781501502620-019Rathjen M. Remarks on Barr’s Theorem: Proofs in Geometric Theories. In: Probst D, Schuster P (ed.)
Concepts of Proof in Mathematics, Philosophy, and Computer Science. Berlin, Boston: De Gruyter; 2016. p.347-374.
https://doi.org/10.1515/9781501502620-019