https://knova.um.edu.my/research_publications_2021_2025/2390/
"Alternating sign property of the perfect matching derangement graph" by Zhi Kang Samuel Koh, Cheng...
It was conjectured in the monograph 9] by Godsil and Meagher and in the article 10] by Lindzey that the per-fect matching derangement graph M2n possesses the...