Addendum to Olivier Schiffmann, "Drinfeld realization of the elliptic   Hall algebra"
  In \cite{S} O. Schiffmann gave a presentation of the Drinfel'd double of the elliptic Hall algebra which is similar in spirit to Drinfel'd's new realization of quantum affine algebras. Using this result together with a part of his proof we can provide such a description for the elliptic Hall algebra. 
Dragos Fratila
math.QA math.CO