| P.T. Geach |
William Heytesbury on 'Insoluble' Sentences: Chapter One of his 'Rules for Solving Sophisms'. Pontifical Institute of Mediaeval Studies, by Paul Vincent Spade |
|
50/1, p. 125 |
| P.T. Geach |
William of Sherwood's Introduction to Logic, by Norman Kretzmann |
|
39/2, p. 180 |
| P.T. Geach |
Medieval Logic and Metaphysics, by D. P. Henry |
|
42/3, p. 269 |