Egbert Harzheim. Combinatorial theorems on contractive mappings in power sets. Discrete Mathematics, 40(2-3):193-201, 1982. [doi]
@article{Harzheim82,
title = {Combinatorial theorems on contractive mappings in power sets},
author = {Egbert Harzheim},
year = {1982},
doi = {10.1016/0012-365X(82)90120-0},
url = {http://dx.doi.org/10.1016/0012-365X(82)90120-0},
tags = {contracts},
researchr = {https://researchr.org/publication/Harzheim82},
cites = {0},
citedby = {0},
journal = {Discrete Mathematics},
volume = {40},
number = {2-3},
pages = {193-201},
}