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