Michael Deutsch. ∞∀∃∀ (ϱ, 1). Math. Log. Q., 35(6):517-529, 1989. [doi]
@article{Deutsch89a,
title = {∞∀∃∀ (ϱ, 1)},
author = {Michael Deutsch},
year = {1989},
doi = {10.1002/malq.19890350607},
url = {http://dx.doi.org/10.1002/malq.19890350607},
researchr = {https://researchr.org/publication/Deutsch89a},
cites = {0},
citedby = {0},
journal = {Math. Log. Q.},
volume = {35},
number = {6},
pages = {517-529},
}