Sloan, David. Ghosts of Key West. Phantom Press (1998). ISBN 978-0-9674498-0-7 „A German citizen, his real name was Carl Tanzler, and though he was well-read in many subjects, it is doubtful that he had any real schooling in the various ...”
crimelibrary.com
A Macabre Love Story. Crime Library. [2006. augusztus 27-i dátummal az eredetiből archiválva]. (Hozzáférés: 2006. augusztus 24.) „Radiologist Carl von Cosel, 56, became obsessed with one of the tuberculosis patients at the sanitarium where he worked. Her name was Maria Elena de Hoyos and she was a beautiful, 22-year-old woman.”
findagrave.com
Find a Grave (angol nyelven). (Hozzáférés: 2019. augusztus 30.)
A Macabre Love Story. Crime Library. [2006. augusztus 27-i dátummal az eredetiből archiválva]. (Hozzáférés: 2006. augusztus 24.) „Radiologist Carl von Cosel, 56, became obsessed with one of the tuberculosis patients at the sanitarium where he worked. Her name was Maria Elena de Hoyos and she was a beautiful, 22-year-old woman.”