1. Double Catalan monoids

   • Volodymyr Mazorchuk
   • Benjamin Steinberg

   OriginalPaper 20 December 2011 Pages: 333 - 354

2. On twin and anti-twin words in the support of the free Lie algebra

   • Ioannis C. Michos

   OriginalPaper 28 December 2011 Pages: 355 - 388

3. On the nullspace of arc-transitive graphs over finite fields

   • Primož Potočnik
   • Pablo Spiga
   • Gabriel Verret

   OriginalPaper 16 December 2011 Pages: 389 - 401

4. Two distance-regular graphs

   • Andries E. Brouwer
   • Dmitrii V. Pasechnik

   OriginalPaper Open access 20 December 2011 Pages: 403 - 407

5. Staircase skew Schur functions are Schur P-positive

   • Federico Ardila
   • Luis G. Serrano

   OriginalPaper 31 January 2012 Pages: 409 - 423

   

6. Foulkes characters, Eulerian idempotents, and an amazing matrix

   • Persi Diaconis
   • Jason Fulman

   OriginalPaper 31 January 2012 Pages: 425 - 440

   

7. Planar flows and quadratic relations over semirings

   • Vladimir I. Danilov
   • Alexander V. Karzanov
   • Gleb A. Koshevoy

   OriginalPaper 28 January 2012 Pages: 441 - 474

   

8. Cluster-additive functions on stable translation quivers

   • Claus Michael Ringel

   OriginalPaper 14 February 2012 Pages: 475 - 500