Antonia wilhelmina fonds :
4e conf. 1929; 5e conf. 1931; 8e conf. 1934; 10e conf. 1937; 12e conf. 1947; 13e conf. 1949; 14e conf. 1951; 15 conf. 1953; 16e conf. 1955; 17e conf. 1957.