Comment on Ihle, "Towards a quantitative kinetic theory of polar active   matter"
  A comment on the preprint "Towards a quantitative kinetic theory of polar active matter" by T. Ihle, arXiv:1401.8056. 
Eric Bertin, Hugues Chat\'e, Francesco Ginelli, Guillaume Gr\'egoire,   S\'ebastien L\'eonard, Anton Peshkov
cond-mat.soft