Jeffrey H. Kingston, Nicholas Paul Sheppard. On the hardness of computing maximum self-reduction sequences. Discrete Mathematics, 226(1-3):243-253, 2001. [doi]
@article{KingstonS01,
title = {On the hardness of computing maximum self-reduction sequences},
author = {Jeffrey H. Kingston and Nicholas Paul Sheppard},
year = {2001},
doi = {10.1016/S0012-365X(00)00132-1},
url = {http://dx.doi.org/10.1016/S0012-365X(00)00132-1},
researchr = {https://researchr.org/publication/KingstonS01},
cites = {0},
citedby = {0},
journal = {Discrete Mathematics},
volume = {226},
number = {1-3},
pages = {243-253},
}