Authors' reply to Page and Rafi. (31st August 2016) - Zeitlin, Jennifer; Manktelow, Bradley N; Piedvache, Aurelie; Cuttini, Marina; Boyle, Elaine; van Heijst, Arno; Gadzinowski, Janusz; Van Reempts, Patrick; Huusom, Lene; Weber, Tom; Schmidt, Stephan; Barros, Henrique; et al.