Malay K. Sen, B. K. Sanyal. Indifference Digraphs: A Generalization of Indifference Graphs and Semiorders. SIAM J. Discrete Math., 7(2):157-165, 1994. [doi]
@article{SenS94,
title = {Indifference Digraphs: A Generalization of Indifference Graphs and Semiorders},
author = {Malay K. Sen and B. K. Sanyal},
year = {1994},
url = {http://epubs.siam.org/sam-bin/dbq/article/17714},
tags = {graph-rewriting, rewriting},
researchr = {https://researchr.org/publication/SenS94},
cites = {0},
citedby = {0},
journal = {SIAM J. Discrete Math.},
volume = {7},
number = {2},
pages = {157-165},
}