Adolf Holzhaus
Adolf Holzhaus was an Esperantist and historian of the Esperanto movement. Between 1959 and 1985, he compiled biographies of the lives of Esperanto creator L. L. Zamenhof and his family, Esperanto pioneer Wilhelm Heinrich Trompeter, and others. He edited and published documents on the history of Esperanto, including Zamenhof's Hillelism and "Provo de gramatiko de novjuda lingvo kaj alvoko al la juda intelektularo".
Holzhaus authored "Vivokuroj de esperantistoj" as an intended replacement for the Encyclopedia of Esperanto. His book, which remained unpublished, now sits in the Esperanto Museum.