Pseudo-conformal quaternionic CR structure on (4n+3)-dimensional   manifolds
  The purpose of this paper is to introduce a geometric structure called pseudo-conformal quaternionic CR structure on a (4n+3)-dimensional mamnifold and then exhibit a quaternionic analogue of Chern-Moser's CR structure and uniformization. 
Dmitri Alekseevsky and Yoshinobu Kamishima