The Hector Hodler Library in Rotterdam, which is devoted to this artificial language, has over 15,000 books
[DOC] [TLE] Jeopary Questions page 1144 - ALSO AN AIRLINE - TriviaBistro.com [PAR] LIBRARIES: The Hector Hodler Library in Rotterdam, which is devoted to this 
artificial language, has over 15,000 books  OLD SONG LYRICS: The Chordettes:
... [DOC] [TLE] Esperanto library - Wikipedia [PAR] The Universala Esperanto-Asocio, which maintains the Hector Hodler Library in 
Rotterdam, Netherlands.