Text and Data Mining valid from 2019-04-02
Received: 21 November 2018
Accepted: 6 March 2019
First Online: 2 April 2019
Compliance with ethical standards
: Mirella Ahonen-Siirtola, Terhi Nevala, Jaana Vironen, Jyrki Kössi, Tarja Pinta, Susanna Niemeläinen, Ulla Keränen, Jaana Ward, Pälvi Vento, Jukka Karvonen, Pasi Ohtonen, Jyrki Mäkelä and Tero Rautio declare that they have no conflicts of interest or financial ties to disclose.