José Manuel Gómez Soto, Andrew Wuensche. X-Rule's Precursor is Also Logically Universal. J. Cellular Automata, 12(6):445-473, 2017. [doi]
@article{SotoW17,
title = {X-Rule's Precursor is Also Logically Universal},
author = {José Manuel Gómez Soto and Andrew Wuensche},
year = {2017},
url = {http://www.oldcitypublishing.com/journals/jca-home/jca-issue-contents/jca-volume-12-number-6-2017/jca-12-6-p-445-473/},
researchr = {https://researchr.org/publication/SotoW17},
cites = {0},
citedby = {0},
journal = {J. Cellular Automata},
volume = {12},
number = {6},
pages = {445-473},
}