@article{1183740516,
author = {Manaster, Alfred B. and Rosenstein, Joseph G.},
title = {Two-Dimensional Partial Orderings: Undecidability},
journal = {J. Symbolic Logic},
volume = {45},
number = {1},
year = {1980},
pages = { 133-143},
language = {en},
url = {http://dml.mathdoc.fr/item/1183740516}
}
Manaster, Alfred B.; Rosenstein, Joseph G. Two-Dimensional Partial Orderings: Undecidability. J. Symbolic Logic, Tome 45 (1980) no. 1, pp. 133-143. http://gdmltest.u-ga.fr/item/1183740516/