1. Constructing partial geometries from overlarge sets of Steiner systems

   • Sven Reichard
   • Andrew Woldar

   Original Paper 12 March 2021 Pages: 1 - 17

2. Propagation of curved folding: the folded annulus with multiple creases exists

   • Leonardo Alese

   Original Paper Open access 16 March 2021 Pages: 19 - 43

   

3. On Bach almost solitons

   • Amalendu Ghosh

   Original Paper 13 February 2021 Pages: 45 - 54

4. Convexity limit angles for isoptics

   • Magdalena Skrzypiec

   Original Paper Open access 04 March 2021 Pages: 55 - 67

   

5. Topology of the tropical moduli spaces \(\Delta _{2,n}\)

   • Melody Chan

   Original Paper 25 February 2021 Pages: 69 - 93

   

6. The classification of convex polygons with triangular area or perimeter bisecting deltoids

   • Allan Berele
   • Stefan Catoiu

   Original Paper 08 April 2021 Pages: 95 - 114

   

7. Poncelet plectra: harmonious curves in cosine space

   • Daniel Jaud
   • Dan Reznik
   • Ronaldo Garcia

   Original Paper 29 September 2021 Pages: 115 - 131

   

8. Some properties of rational conic fibrations

   • Antonio Lanteri
   • Raquel Mallavibarrena

   Original Paper 07 January 2021 Pages: 133 - 147

9. Reducibility of n-ary semigroups: from quasitriviality towards idempotency

   • Miguel Couceiro
   • Jimmy Devillet
   • Pierre Mathonet

   Original Paper 09 January 2021 Pages: 149 - 166

10. Higher order z-ideals of special rings

    • Ahmed Maatallah
    • Ali Benhissi

    Original Paper 10 January 2021 Pages: 167 - 177

11. Descent of properties of rings and pairs of rings to fixed rings

    • Ravinder Singh

    Original Paper 26 February 2021 Pages: 179 - 187

12. On finite dimensionality of Chow groups

    • Kalyan Banerjee

    Original Paper 17 March 2021 Pages: 189 - 207

13. The McCoy property in Ohm–Rush algebras

    • Neil Epstein

    Original Paper 10 March 2021 Pages: 209 - 214

14. Correction to: The McCoy property in Ohm–Rush algebras

    • Neil Epstein

    Correction 07 April 2021 Pages: 215 - 215