Volume 77 (2020)
Part 1
- Kean Fallon, Colin Giles, Hunter Rehm, Simon Wagner and Nathan Warnberg
- Mehtaab Sawhney and David Stoner
- Aleksandar Bikov and Nedyalko Nenov
- Colin Defant and Noah Kravitz
- Stack-sorting for words, pp.51–68
- Masao Tsugaki and Tomoki Yamashita
- Douglas R. Stinson and Shannon Veitch
- N. N. Avdeev
- Julien Bensmail, Soumen Nandi, Mithun Roy and Sagnik Sen
- Ruixia Wang and Linxin Wu
Part 2
- Kelly Guest, Sarah Holliday, Peter Johnson, Dieter Rautenbach and Matthew Walsh
- Closed-neighborhood union-closed graphs, pp.144–156
- Béata Bényi, José L. Ramirez and Miguel Méndez
- Generalized ordered set partitions, pp.157–179
- Gábor Hegedűs
- Difference sets and power residues, pp.180–183
- Eric Swartz and Nicholas J. Werner
- On the number of reachable pairs in a digraph, pp.184–223
- Yuanqiu Huang, Tinglei Zhao and Zongpeng Ding
- Sam Spiro
- S. Nazari-Moghaddam and M. Chellali
- On the double Roman domination number in trees, pp.256–268
- Guifu Su, Zihao Li and Huichao Shi
- Michal Parnas and Adi Shraibman
Part 3
- Weili Guo and Michele Torielli
- Jeremiah Bartz, Bruce Dearden and Joel Iiams
- Christopher R.H. Hanusa and Thomas Zaslavsky
- Mario Gionfriddo, Lorenzo Milazzo and Zsolt Tuza
- Hypercycle systems, pp.336–354
- Ronald J. Gould, Kazuhide Hirohata and Ariel Keller Rorabaugh
- Paul Renteln
- Some constraints on the missing Moore graph, pp.373–382
- Cong X. Kang, Gretchen L. Matthews and Justin D. Peachey
- On Laplacian monopoles, pp.383–397
- Adrian Beker
- The star avoidance game, pp.398–405