This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Per.huttner. Per Httner drawing detail Transferred from org en Original text selfmade Prallman talk Original uploader was Prallman at org en Released into the public domain by the author en Prallman Original upload log page en Per huttner Prallman bytes no per huttner drawing detail selfmade Per Httner