David Ullrich, Michael Byrd. 3. J. Philosophical Logic, 6(1):109-117, 1977. [doi]
@article{UllrichB77,
title = {3},
author = {David Ullrich and Michael Byrd},
year = {1977},
doi = {10.1007/BF00262052},
url = {http://dx.doi.org/10.1007/BF00262052},
researchr = {https://researchr.org/publication/UllrichB77},
cites = {0},
citedby = {0},
journal = {J. Philosophical Logic},
volume = {6},
number = {1},
pages = {109-117},
}