Public domain
Poster showing scientific illustrations of butterfly specimens, taken in the Academy of Sciences, St. Petersburg
From the collection of Library of Congress. Free to download, adapt and use — no permission needed.
Credit linePoster showing scientific illustrations of butterfly specimens, taken in the Academy of Sciences, St. Petersburg. 1905-01-01. Prokudin-Gorskiĭ, Sergeĭ Mikhaĭlovich. Prokudin-Gorskii Collection, Library of Congress. Public domain.