Louis W. Shapiro, A. B. Stephens. Bootstrap Percolation, the Schröder Numbers, and the ::::N::::-Kings Problem. SIAM J. Discrete Math., 4(2):275-280, 1991.
@article{ShapiroS91,
title = {Bootstrap Percolation, the Schröder Numbers, and the ::::N::::-Kings Problem},
author = {Louis W. Shapiro and A. B. Stephens},
year = {1991},
researchr = {https://researchr.org/publication/ShapiroS91},
cites = {0},
citedby = {0},
journal = {SIAM J. Discrete Math.},
volume = {4},
number = {2},
pages = {275-280},
}