1 1 20 An International Study in Denmark, Estonia, Germany and Sweden Anette Sandberg Primary Author Stig Brostro¨m Primary Author Inge Johansson Primary Author Thorleif Frøkjær Primary Author Christa Kieferle Primary Author Anja Seifert Primary Author Angela Roth Primary Author Maire Tuul Primary Author Aino Ugaste Primary Author Meeli Laan Primary Author mixed material 15731707 New York New York:Springer 2017 5.jpg.jpg