Widmer, Christian
Lippert, Christoph
Weissbrod, Omer
Fusi, Nicolo
Kadie, Carl
Davidson, Robert
Listgarten, Jennifer
Heckerman, David
Article History
Received: 9 August 2013
Accepted: 14 October 2014
First Online: 12 November 2014
Competing interests
: C.W., C.L., N.F., C.K., R.D., J.L. and D.H. were employed by Microsoft while performing this work.