Loe M. G. Feijs, René L. Krikhaar. Relation algebra with multi-relations. Int. J. Comput. Math., 70(1):57-74, 1998. [doi]
@article{FeijsK98,
title = {Relation algebra with multi-relations},
author = {Loe M. G. Feijs and René L. Krikhaar},
year = {1998},
doi = {10.1080/00207169808804736},
url = {https://doi.org/10.1080/00207169808804736},
researchr = {https://researchr.org/publication/FeijsK98},
cites = {0},
citedby = {0},
journal = {Int. J. Comput. Math.},
volume = {70},
number = {1},
pages = {57-74},
}