Subramanian, C. R. “Finding Induced Acyclic Subgraphs in Random Digraphs”. The Electronic Journal of Combinatorics 10, no. 1 (December 4, 2003): #R46. Accessed May 30, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v10i1r46.