Sergio Bermudo, Henning Fernau. Computing the differential of a graph: Hardness, approximability and exact algorithms. Discrete Applied Mathematics, 165:69-82, 2014. [doi]
@article{BermudoF14,
title = {Computing the differential of a graph: Hardness, approximability and exact algorithms},
author = {Sergio Bermudo and Henning Fernau},
year = {2014},
doi = {10.1016/j.dam.2012.11.013},
url = {http://dx.doi.org/10.1016/j.dam.2012.11.013},
researchr = {https://researchr.org/publication/BermudoF14},
cites = {0},
citedby = {0},
journal = {Discrete Applied Mathematics},
volume = {165},
pages = {69-82},
}