By Ren
William Wallace Denslow (American, 1856 – 1915)
National Institutes of Health (American, 1887-)
Hermann Kern (Austrian, 1838-1912)
Theodor Barth (Swiss, 1875 - 1949)
Osmar Schindler (German, 1867-1927)
Percy J. Billinghurst (English, 1871-1933)
John Covert (American, 1882 – 1960)