Citations of: Layman E. Allen. Propositional calculi. MULL, vol. 59 no. S , pp. 4–14. - Layman E. Allen. Alethic logic. MULL, vol. 59 no. D , pp. 33–42. - Layman E. Allen. Deontic logic. MULL, vol. 60 no. M , pp. 13–27. - Layman E. Allen. Note on simplifying the reiteration rule. MULL, vol. 59 no. D , p. 42. - Layman E. Allen. Note on the use of definitions to justify steps in proofs. MULL, vol. 59 no. D , pp. 42–44