Iiro S. Honkala. All binary codes with covering radius one are subnormal. Discrete Mathematics, 94(3):229-232, 1991. [doi]
@article{Honkala91-0,
title = {All binary codes with covering radius one are subnormal},
author = {Iiro S. Honkala},
year = {1991},
doi = {10.1016/0012-365X(91)90028-Z},
url = {http://dx.doi.org/10.1016/0012-365X(91)90028-Z},
researchr = {https://researchr.org/publication/Honkala91-0},
cites = {0},
citedby = {0},
journal = {Discrete Mathematics},
volume = {94},
number = {3},
pages = {229-232},
}