Mani, Arun P. “An Extension of Matroid Rank Submodularity and the $Z$-Rayleigh Property”. The Electronic Journal of Combinatorics 18, no. 1 (May 16, 2011): P113. Accessed March 17, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v18i1p113.