1  M. D. Gustav Langmann (21 Dec 1842 – 1916 New York, USA)   +  Cathy Zinser (1858 – 1931)      2  Book Dealer Heinrich Langmann (Apr 1883 – 1947 New York, USA)         +  Catherine Campbell       2  Builder/New York Otto Friedel Langmann (Dec 1884 – )         +  Catherine O’Byrne       2  M. D. Alfred Langmann (Apr 1890 New York, USA – )         +  Margot Nesse       2  Emily Helen Langmann (Dec 1896 – )         +  Earl van Derwerker (1890 – 1947)            3  Jean Helen van Derwerker                +  Leonard Burgen                   4  Linda Burgen (1945 – )            3  Earl van Derwerker