European Federation of Associations of Teachers of the Deaf

• 
  Kommunikationsstorungen: 7. Kongress Fribourg, 29-31.10. 1981
  by European Federation of Associations of Teachers of the Deaf
  Hardcover, J. Groos, ISBN 3872762850 (3-87276-285-0)
• 
  Spracherwerb, Aber Wie: 8. Kongress, Sigtuna, 4.-6.11.1983
  by European Federation of Associations of Teachers of the Deaf
  Hardcover, J. Groos, ISBN 3872765329 (3-87276-532-9)