https://roysnaturelogbook.blogspot.com/2013/08/clouded-yellow-butterfly.html
Roy's Nature Logbook: Clouded Yellow Butterfly
Before today the only occasion I had observed a Clouded Yellow Butterfly was in Tuscany. This species is an immigrant to UK from Southern...
roy sclouded yellownaturelogbookbutterfly
https://www.museum.zoo.cam.ac.uk/butterflies/butterflies-through-time/pieridae/clouded-yellow-pale-clouded-yellow
clouded yellow & pale clouded yellow | Museum of Zoology
clouded yellowpalemuseumzoology