Kompensatorische Spracherziehung in der Vor- und Grundschule /
Gahagan, Denis Michael.
Gahagan, Georgina Ann.
Petersen, Hans.
Düsseldorf :  Pädagogischer Verlag Schwann, 
1974.
Translation of: Talk reform. Explorations in language for infant school children. Originally published, London: Routledge & Kegan Paul, 1970.