Reupload from Collection on Wikicommons - URL https://secure.wikimedia.org/wikipedia/commons/wiki/File:General-strike.svg information about why this image is in the public domain can be found there.
This clipart is a remake from a book by Hans Rudolf Lutz
"Today's Hieroglyphs", Niggli Verlag, septembre 2009
All the illustration of this book are in public domain.