1. Thudichum. Letter to Virchow: 19th October 1869 reproduced in Thudichum: chemist of the brain (see Reference 20).
2. ThudichumFriedrich Wolfgang Karl. Geschicte des Geschlectes Thudichum. Tübingen: W Armbruster & O Riecker, 1893 (Erster Thail 131):131.
3. Urochrome; the Colouring Matter of Urine