Esperanto Congress Oostende
Esperanto - S.A.T. Congress Amersfoort
Esperanto
Esperanto - 100 years of international language
Esperanto Congress
Esperanto Jubilee Congress
Esperanto Congress Haarlem
International Esperanto Congress Haarlem
Esperanto - S.A.T. Congress Rotterdam
Esperanto Domo Arnhem
Esperanto - S.A.T. Congress Amsterdam
I.K.U.E. Esperanto Congress The Hague
Esperanto F.L.E. Heerlen
S.A.T. Esperanto Congress Amsterdam
F.L.E. Esperanto Congress Heerlen
Esperanto - Stamp Centenary - Airmail