Roger D. Maddux. The Equational Theory of CA::3:: is Undecidable. Journal of Symbolic Logic, 45(2):311-316, 1980.
@article{Maddux80, title = {The Equational Theory of CA::3:: is Undecidable}, author = {Roger D. Maddux}, year = {1980}, researchr = {https://researchr.org/publication/Maddux80}, cites = {0}, citedby = {0}, journal = {Journal of Symbolic Logic}, volume = {45}, number = {2}, pages = {311-316}, }